Eyestrain Is Thought to Be Associated with Different Types of Office

Essay

Eyestrain is thought to be associated with different types of office work. The AcmeTemp-Help Company provides short-term employees to substitute for vacationingdata entry workers. Previous research has shown that approximately 21% of full timedata entry workers have eyestrain, and Acme would like to estimate the proportion,p , of their 6,000 part-time data entry employees that have eyestrain.
a) They would like to estimate p to within 0.05 with 95% confidence. If they acceptthe value of 0.21 for full-time data entry workers as a reasonable initial estimateof p, what sample size should they use for their study?
b) Suppose Acme believed that the working conditions of their temporary data entrypersonnel are different enough that they should not depend on the 0.21 as aninitial estimate. In a few sentences, explain how your procedure for choosing asamples size would differ from your solution in part (a). (Do NOT recalculate anew estimate of the necessary sample size!)