An Accounting fiRm Is Planning for the Next Tax Preparation

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 that the mean completion time is between 1 and 2 hours, i.e., 60 and 120
Minutes?

A) Approximately 1
B) 0.1664
C) 0.8336
D) 0.9676