An accounting firm is planning for the next tax preparation season. From last year's returns, the firm collects a systematic random sample of 100 filings. The 100 filings showed an average preparation time of 90 minutes with a standard deviation of 140 minutes.
What is the standard error of the mean?
A) 14 minutes
B) 140 minutes
C) 1.4 minutes
D) 90 minutes
E) None of the choices are correct

Question

Quizplus · Accepted Answer

The standard error of the mean is calculated by dividing the standard deviation by the square root of the sample size. In this case, the standard deviation is 140 minutes and the sample size is 100. Therefore, the standard error of the mean is 140 minutes / sqrt(100) = 14 minutes.

An Accounting Firm Is Planning for the Next Tax Preparation