Cable-TV home shoppers. All cable television companies carry at least one home-shopping channel. Who uses these home-shopping services? Are the shoppers primarily men or women? Suppose you want to estimate the difference in the percentages of men and women who say they have used or expect to use televised home shopping. You want a 90% confidence interval of width .06 or less.

a. Approximately how many people should be included in your samples?

b. Suppose you want to obtain individual estimates for the two percentages of interest. Will the sample size found in part a be large enough to provide estimates of each percentage correct to within .02 with probability equal to .95? Justify your response.