A random sample is drawn from a normally distributed population with mean μ = 12 and standard deviation σ = 1.5. [You may find it useful to reference the z table.].
a. What is the expected value and the standard error of the sampling distribution of the sample mean with n = 20 and n = 40. (Round the standard error to 3 decimal places.)
b. Can you conclude that the sampling distribution of the sample mean is normally distributed for both sample sizes?
multiple choice 1
Yes, both the sample means will have a normal distribution.
No, both the sample means will not have a normal distribution.
No, only the sample mean with n = 20 will have a normal distribution.
No, only the sample mean with n = 40 will have a normal distribution.
c. If the sampling distribution of the sample mean is normally distributed with n = 20, then calculate the probability that the sample mean is less than 12.5. (If appropriate, round final answer to 4 decimal places.)
multiple choice 2
We cannot assume that the sampling distribution of the sample mean is normally distributed.
We can assume that the sampling distribution of the sample mean is normally distributed and the probability that the sample mean is less than 12.5 is
d. If the sampling distribution of the sample mean is normally distributed with n = 40, then calculate the probability that the sample mean is less than 12.5. (If appropriate, round final answer to 4 decimal places.)
multiple choice 3
We cannot assume that the sampling distribution of the sample mean is normally distributed.
We can assume that the sampling distribution of the sample mean is normally distributed and the probability that the sample mean is less than 12.5 is