A population that consists of 500 observations has a mean of 40 and a standard deviation of 15.A sample of size 100 is taken at random from this population.The standard error of the sample mean equals:
A) 2.50.
B) 12.50.
C) 1.343.
D) 1.50.

Question

Quizplus · Accepted Answer

The standard error of the sample mean is equal to the population standard deviation divided by the square root of the sample size. In this case, the population standard deviation is 15 and the sample size is 100, so the standard error of the sample mean is 15 / sqrt(100) = 1.5.

A Population That Consists of 500 Observations Has a Mean