The manager of a grocery store has taken a random sample of 144 customers. The average length of time it took these 144 customers to check out was 3 minutes. It is known that the standard deviation of the population of checkout times is 1 minute. The standard error of the mean equals
A) .008.
B) .833.
C) .083.
D) 1.000.

Question

Quizplus · Accepted Answer

The formula for standard error of the mean is standard deviation divided by the square root of the sample size. Therefore, the standard error of the mean in this case is 1 / sqrt(144) = 0.083.

The Manager of a Grocery Store Has Taken a Random