13. A score that is 9 points above the mean corresponds to a z-score of z = 1.50. What is the population standard deviation?

Q: Suppose that a distribution of 400 items has mean 130 and standard deviation 5. Find the​ z-score of…

A: Given that.   X~N( μ , ?)   μ=130     , ?=5  , x=143   Z-score =( x - μ )/?

Q: On a recent quiz, the class mean of 74 with the standard deviation of 3.9.  calculate the z-score…

A: Given data  μ = 74σ = 3.9x1 = 95x2 = 70

Q: A variable is normally distributed with mean 10 and standard deviation 3. Find the percentage of all…

A:

Q: A variable is normally distributed with mean 10 and standard deviation 3. Find the percentage of all…

A: Given  μ =10,σ=3 X~N(μ =10,σ2 =32)  We want to find the probability  P(73<X<80)= ?  Note: This…

Q: Assume that the number of pieces per bag has a mean of 72 with a standard deviation of 1.use the…

A: We have to find given probability by using emperical rule...

Q: An IQ score has a mean, u = 90, and standard deviation, o = 10. (5PTS EACH) 1. A genius is sometimes…

A: 5. Mean = 100, Stdev = 10 a. PX≥140 = PZ≥ 140-100 10 = P(Z≥ 4) = 0.000031

Q: A set of test papers is normally distributed with a standard deviation of 5. If Riley scored an 83…

A:

Q: Approximately what percentage of normally distributed data values will fall within 2 standard…

A: It is known that, normal curve is a symmetric and bell shaped distribution.

Q: IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Find the IQ…

A: Excel formula: =NORMINV(0.305,0,1)=-0.5100

Q: A normal distribution has a mean of 175 and a standard deviation of 38. What percent of observations…

A: Given that A Normal distribution has Mean (μ) = 175 Standard deviation (σ) = 38   We know that Z =…

Q: Suppose that IQ scores have a bell shaped distribution with a mean of 101 and a standard deviation…

A: The IQ scores have a bell shaped distribution with a mean of 101 and a standard deviation of 17.

Q: Assume that the amount of time a person experiences cold virus symptoms are normally distributed…

A: Given data Mean = 7.5 days  Standard deviation  = 1.5d days To find: What proportion of cold…

Q: how do you find the standard deviation when the score is 9 points above tthe mean?

A: = population standard deviation = the size of the population = each value from the population =…

Q: IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What…

A: Obtain the z-score for the random variable X equals 85. The z-score for the random variable X equals…

Q: Suppose the exam average in a class is 82% with a standard deviation of 2. What proportion of…

A:

Q: IQ scores have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. a. What…

A: Given DataMean = 100Standard Deviation = 15

Q: The scores for a standardized test follow a normal distribution with a mean test score of x = 84,…

A:

Q: Suppose that the score on a reading test are normally distributed within a mean of 70 and a standard…

A: