Random samples of size 81 are taken from 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 mean 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 is 200, which will also be the mean of the sampling distribution of the mean.
The standard error of the mean (SEM) will be the standard deviation of the sampling distribution, which is equal to the population standard deviation divided by the square root of the sample size:
SEM = 18 / sqrt(81) = 2.

Therefore, the answer is D - 200 and 2.

Random Samples of Size 81 Are Taken from an Infinite