Random samples of size 81 are taken from a process (an infinite population) whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the distribution of sample means are _____.
A) 200 and 18
B) 81 and 18
C) 9 and 2
D) 200 and 2

Question

Quizplus · Accepted Answer

The mean of the population, 200, will be the mean of the distribution of sample means. The standard error of the distribution of sample means can be calculated as the standard deviation of the population divided by the square root of the sample size: 18/sqrt(81) = 2. Therefore, the mean and the standard error of the distribution of sample means are 200 and 2, respectively.

Random Samples of Size 81 Are Taken from a Process