Suppose x has a distribution with a mean of 90 and a standard deviation of 27. Random samples of of size n =36 are drawn.     Find the z value corresponding to x =85.5

Suppose X has a normal distribution with mean 80 and standard deviation 5. How many standard deviations above or below the mean is 70? None of the other choices is correct 10 standard deviations below the mean O2 standard deviations above the mean 2 standard deviations below the mean

When samples of size 30 are collected from a normal population that has a mean of 200 and a standard deviation of 40, the standard deviation of the sampling distribution is?

A population has a mean μ=158 and a standard deviation σ=21. Find the mean and standard deviation of the sampling distribution of sample means with sample size n=47.

Suppose that heights of 10-year-old boys in the US vary according to a normal distribution with mean of 138 cm and standard deviation of 7. Compute the Z-score for a boy with height of 150 cm and find the correct interpretations.   a. Boy's height is 0.71 standard deviation lower the national average   b. Boy's height is 1.71 standard deviation above the national average   c. Boy's height is 1.71 standard deviation lower than the national average   d. Boy's height is 2.71 standard deviation above the national average

Suppose that a sample of size 52 is drawn from a population with mean 23 and standard deviation 39 . Find the value of , the standard deviation of the distribution of sample means.

A population has a mean μ=85 and a standard deviation σ=21. Find the mean and standard deviation of a sampling distribution of sample means with sample size n=263.

A population is known to be normally distributed with standard deviation known to be 8.5.  In order to test the hypothesis that the true value of the mean is 17 researchers collect a sample of size 33 and calculate the sample mean to be 14.  State the distribution of the sample mean and then test this hypothesis using the appropriate test.