An Accounting Firm Is Planning for the Next Tax Preparation

Multiple Choice

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 probability of finding a sample mean less than 18 hours?

A) 0.4820
B) 0.4920
C) 0.0080
D) 0.0180
E) None of the choices are correct