For single proportion fhte margin of error of a confidence interval is largest for any given sample size n as well as confidence level C when p(hat)=0.5. This led us to employ p*=0.5 for planning purposes. The same type of results is true for the two-sample problem. The margin of error of confidence interval for the difference between two proportions is largest when p(hat)1=p(hat)2=0.5. You're planning a survey and will compute a 95% confidence interval for the difference in two proportions when the data are gathered. You would like the margin of error of the interval to be less than or equal to 0.075. You will employ the same sample size n for both populations.
a) How large a value of n is required?
b) Give a general formula for n in terms of desired margin of error m and the critical value z*.