A study on the length of time a person brushes their teeth is conducted on a large population of adults. The mean brushing time is μ and the standard deviation is σ. A simple random sample of 160 adults is considered. (NOTE: For the following problems, write: '' GREATER THAN '', '' EQUAL TO '', '' LESS THAN '', or '' NOT ENOUGH INFORMATION '')   (a) The mean of the sampling distribution for X¯ is____________the mean of the population.   (b) The standard deviation of the sampling distribution for X¯ is ____________the standard deviation of the population.

Q: 4. There were 17 sophomores who took this course with a mean score of 66.5 and a standard deviation…

A: (a)   State the hypotheses.   Obtain the degrees of freedom.   The degrees of freedom formula for…

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Q: . Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed…

A: Solution

Q: The heights of 700 students are approximately normally distributed with a mean of 175 centimeters…

A: Given,mean(μ)=175standard deviation(σ)=7sample size(n)=25

Q: 4. Cholesterol levels are measured for 12 heart attack patients (2 days after their attacks) and 14…

A: For the given data Perform t test for two means

Q: 5. On an examination the average grad the class are given A's, and the grade the lowest possible A…

A: Given data,X=74σ=7P(X>x)=12%=0.12Mean(μ)=?

Q: 6. Given a normal distribution with a mean of 400 and a standard deviation of 60, find the…

A:

Q: The mark of a statistics test is normally distributed with mean μ and standard deviation σ. 5% of…

A: 9.

Q: According to AC Lens, green eye color is one of the rarest with only 2% of the world's population…

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A: Given X is normal Distributed with mean µ = 44000.0 and standard deviation σ = 12355.0 now will…

Q: Dr. Smith initially decides to curve the class scores according to the following criteria relative…

A: Given Information: Mean μ=78 Standard deviation σ=8

Q: 4. An aptitude test has a mean of 230 and a standard deviation of 15. Find the corresponding z-…

A: Bartleby policy: Since you have asked multiple question, we will solve the first question for you.…

Q: A recent study stated that if a person chewed gum, the average number of sticks of gum he or she…

A: Givensample size(n)=36Mean(x)=8standard deviation(s)=1α=0.05

Q: 12. A sample has a mean M = 50. In the sample, a score of X = 41 corresponds to z = -1.50. What is…

A:

Q: 9. What is the z-score of x = 7 if it is 0 standard deviations to the left of the mean? a. z = +1.00…

A:

Q: A. n (no of data in the set) = Mean: E* с. Variance = 2(x-mean)² n-1 D. Standard deviation = square…

A: 4. The sums are, Number x x-mean x-mean2 15 -24.5455 602.4816 36 -3.5455 12.5706 45 5.4545…

Q: 10. Suppose a distribution for X is normally distributed with a mean of 30 and standard deviation of…

A: Given: Margin of Error E = 0.4 Mean  μ = 30 Standard deviation  σ=0.4 Sample size  n=25

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A:

Q: A researcher took a random sample of 25 observations from a normal population with a standard…

A: It is given that the sample size is n=25.The population standard deviation is σ=50.The population is…

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A:

Q: 10. The distribution of the weights of loaves of bread from a certain bakery follows approximately a…

A: given data  P(x<15.34) = 0.10 P(x>16.31) = 0.20 μ = ?σ = ?

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A: 4. Given that μ=75 and σ=8 The teacher given A to the students who score 90 and above. Consider, the…

Q: 8) It is known that 41% of the population in the United States have brown eyes. Find the mean and…

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A: is a random variable for machine 1 and is a random variable for machine 2.Machine 1sample size is…

Q: 2. The scores on a competency test for 2nd-year high school students have a normal distribution with…

A: Mean(µ) = 400 Standard deviations (σ) = 100 X ~ N (µ, σ )= N ( 400, 100)

Q: 4. The SAT scores of the incoming freshmen class are normally distributed with a mean of 1100 and…

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A:

Q: 4. The following is the distribution of the daily emission of sulfur oxides by an industrial plant.…

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Q: Suppose that you are interested in the number of people in each household in the U.S. Your sample…

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Q: 1. A population is normally distributed with a mean of -30 (negative 30) and a standard deviation of…

A: 1. The mean is -30, and standard deviation is 4.

Q: 6) A normal distribution has mean 500 and variance 2500. Find the area under the normal curv the…

A:

Inverse Normal Distribution

The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.

Mean, Median, Mode

It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.

Z-Scores

A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.