Rachel Robertson wishes to use mean-per-unit sampling to evaluate the reasonableness of the book value of the accounts receivable of Smith, Inc. Smith has 11,600 receivable accounts with a total book value of $1,650,000. Robertson estimates the population's standard deviation to be equal to $29. After examining the overall audit plan, the auditors believe that the account's tolerable misstatement is $67,000, and that a risk of incorrect rejection of 10 percent and a risk of incorrect acceptance of 20 percent are appropriate. Use Figure 9.8.

Required:

a. Calculate the required sample size. (Do not round any division. Round other computations and the final answer to the next whole number.)