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 will be more than 120 minutes?
A) Approximately zero
B) 0.0832
C) 0.4168
D) 0.0162

Question

Quizplus · Accepted Answer

To find the probability that the mean completion time will be more than 120 minutes, we need to calculate the z-score and look up the corresponding probability in the standard normal distribution table.

z-score = (120 - 90) / (140 / sqrt(100)) = 30 / 14 = 2.14

Using the standard normal distribution table, the probability of z-score being greater than 2.14 is approximately 0.0162.

Therefore, the answer is D.

An Accounting Firm Is Planning for the Next Tax Preparation