(A)What Sample Size Would Be Required for the Production Personnel

Essay

(A)What sample size would be required for the production personnel to be approximately 95% sure that their estimate of the average number of errors per issue is within 4 errors of the true mean? Assume that the editor's best estimate of the population standard deviation ( )is 10 errors per issue.
(B)How does your answer to (A)change if the editor wants the estimate to be within 3 errors of the actual population mean? Explain the difference in your answers to (A)and (B).