Random samples of size 36 are taken from a process (an infinite population) whose mean and standard deviation are 20 and 15, respectively. The distribution of the population is unknown. The mean and the standard error of the distribution of sample mean are _____.
A) 36 and 15
B) 20 and 15
C) 20 and 0.417
D) 20 and 2.5

Question

Quizplus · Accepted Answer

The mean of the distribution of the sample mean is the same as the population mean, which is 20. The standard error of the sample mean is the population standard deviation divided by the square root of the sample size, which is 15/√36 = 2.5.

Random Samples of Size 36 Are Taken from a Process