31. what is the frequency of the sample mean 12.5?
A. 0
B. 1
C. 2
D. 3

32. Which of the following is described as the quotient of the population variance and the sample size n?
A. Mean of the sampling distribution of sample mean
B. Variance of the sampling distribution of the sample mean
C. Standard deviation of the sampling distribution of the sample mean
D. Average deviation of the sampling distribution of the sample mean