To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

Question

Want to see more full solutions like this?

Answer 1

Question

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

(b)

To determine

To find out what percent of adults would qualify for membership.

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Students have asked these similar questions

Microsoft Excel snapshot for random sampling: Also note the formula used for the last column 02 x✓ fx =INDEX(5852:58551, RANK(C2, $C$2:$C$51)) A B 1 No. States 2 1 ALABAMA Rand No. 0.925957526 3 2 ALASKA 0.372999976 4 3 ARIZONA 0.941323044 5 4 ARKANSAS 0.071266381 Random Sample CALIFORNIA NORTH CAROLINA ARKANSAS WASHINGTON G7 Microsoft Excel snapshot for systematic sampling: xfx INDEX(SD52:50551, F7) A B E F G 1 No. States Rand No. Random Sample population 50 2 1 ALABAMA 0.5296685 NEW HAMPSHIRE sample 10 3 2 ALASKA 0.4493186 OKLAHOMA k 5 4 3 ARIZONA 0.707914 KANSAS 5 4 ARKANSAS 0.4831379 NORTH DAKOTA 6 5 CALIFORNIA 0.7277162 INDIANA Random Sample Sample Name 7 6 COLORADO 0.5865002 MISSISSIPPI 8 7:ONNECTICU 0.7640596 ILLINOIS 9 8 DELAWARE 0.5783029 MISSOURI 525 10 15 INDIANA MARYLAND COLORADO

Suppose the Internal Revenue Service reported that the mean tax refund for the year 2022 was $3401. Assume the standard deviation is $82.5 and that the amounts refunded follow a normal probability distribution. Solve the following three parts? (For the answer to question 14, 15, and 16, start with making a bell curve. Identify on the bell curve where is mean, X, and area(s) to be determined. 1.What percent of the refunds are more than $3,500? 2. What percent of the refunds are more than $3500 but less than $3579? 3. What percent of the refunds are more than $3325 but less than $3579?

A normal distribution has a mean of 50 and a standard deviation of 4. Solve the following three parts? 1. Compute the probability of a value between 44.0 and 55.0. (The question requires finding probability value between 44 and 55. Solve it in 3 steps. In the first step, use the above formula and x = 44, calculate probability value. In the second step repeat the first step with the only difference that x=55. In the third step, subtract the answer of the first part from the answer of the second part.) 2. Compute the probability of a value greater than 55.0. Use the same formula, x=55 and subtract the answer from 1. 3. Compute the probability of a value between 52.0 and 55.0. (The question requires finding probability value between 52 and 55. Solve it in 3 steps. In the first step, use the above formula and x = 52, calculate probability value. In the second step repeat the first step with the only difference that x=55. In the third step, subtract the answer of the first part from the…

Answer 2

Question

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

(b)

To determine

To find out what percent of adults would qualify for membership.

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 3

Question

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

(b)

To determine

To find out what percent of adults would qualify for membership.

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 4

Question

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

(b)

To determine

To find out what percent of adults would qualify for membership.

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 5

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

(b)

To determine

To find out what percent of adults would qualify for membership.

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Answer 6

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

Answer 7

Chapter 11, Problem 11.25E

(a)

To determine

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

Answer 8

(a)

Expert Solution

Answer to Problem 11.25E

50% of people have WAIS scores above 100 , 0.15% of people have WAIS scores above 145 and 16% of people have WAIS scores below 85 .

Answer 9

(a)

Expert Solution

Answer 10

(a)

Expert Solution

Answer 11

Expert Solution

Answer 12

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of people have WAIS scores above 100 we have that 100 is the mean of the data then we can say that about 50% of people have WAIS scores above 100 as mean is the center of the normal graph.

And to calculate the percent of people have WAIS scores above 145 , we have,

First calculate the z -value as,

z=x−μσ=145−10015=3

So, it has three standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.9972=0.0015=0.15%

Thus, 0.15% of people have WAIS scores above 145 .

And to calculate the percent of people have WAIS scores below 85 , we have,

First calculate the z -value as,

z=x−μσ=85−10015=−1

So, it has one standard deviation below the mean so, using 68−95−99.7 rule we have,

=1−0.682=0.16=16%

Thus, 16% of people have WAIS scores below 85 .

Answer 13

(b)

To determine

To find out what percent of adults would qualify for membership.

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

Answer 14

(b)

To determine

To find out what percent of adults would qualify for membership.

Answer 15

(b)

Expert Solution

Answer to Problem 11.25E

2.5% of adults would qualify for membership.

Answer 16

(b)

Expert Solution

Answer 17

(b)

Expert Solution

Answer 18

Expert Solution

Answer 19

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults would qualify for membershipfor which scores should be 130 or higher, we have,

First calculate the z -value as,

z=x−μσ=130−10015=2

So, it has two standard deviations above the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults would qualify for membership.

Answer 20

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Answer 21

(c)

To determine

To find out about what percent of adults are mentally retarded according to this criterion.

Answer 22

(c)

Expert Solution

Answer to Problem 11.25E

2.5% of adults are mentally retarded according to this criterion.

Answer 23

(c)

Expert Solution

Answer 24

(c)

Expert Solution

Answer 25

Expert Solution

Answer 26

Explanation of Solution

In the question, it is given that the scale of scores is set separately for each age group and is approximately Normal with mean 100 and standard deviation 15 . We will use 68−95−99.7 rule to solve the problem. As we know that the empirical rule, also known as the three-sigma rule or the 68−95−99.7 rule, provides a quick estimate of the spread of data in a normal distribution given the mean and standard deviation. Specifically, the empirical rule states that for a normal distribution:

68% of the data will fall within one standard deviation of the mean.

95% of the data will fall within two standard deviations of the mean.

Almost all 99.7% of the data will fall within three standard deviations of the mean.

Thus, to calculate the percent of adults are mentally retarded according to this criterion for which scores should be 70 or lower, we have,

First calculate the z -value as,

z=x−μσ=70−10015=−2

So, it has two standard deviations below the mean so, using 68−95−99.7 rule we have,

=1−0.952=0.025=2.5%

Thus, 2.5% of adults are mentally retarded according to this criterion.

Answer 27

Ch. 11 - Prob. 11.1AYK Ch. 11 - Prob. 11.2AYK Ch. 11 - Prob. 11.3AYK Ch. 11 - Prob. 11.4AYK Ch. 11 - Prob. 11.5AYK Ch. 11 - Prob. 11.6AYK Ch. 11 - Prob. 11.7AYK Ch. 11 - Prob. 11.8AYK Ch. 11 - Prob. 11.9AYK Ch. 11 - Prob. 11.10AYK

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

To find out what percentof people have WAIS scores above 100 and above 145 and below 85 .

Answer to Problem 11.25E

Explanation of Solution

To find out what percent of adults would qualify for membership.

Answer to Problem 11.25E

Explanation of Solution

To find out about what percent of adults are mentally retarded according to this criterion.

Answer to Problem 11.25E

Explanation of Solution

Want to see more full solutions like this?

Chapter 11 Solutions