3. A particular Dunkin store wishes to determine the proportion of customers served within two minutes of ordering.

a. What size sample is necessary to make a 98% confidence interval estimate for the proportion of customers served within two minutes of ordering with a maximum error of 1.5%?

b. They believe 78.7% of customers are served within two minutes of ordering. Assuming this is correct, what size sample is now necessary to calculate a 98% confidence interval estimate for the proportion of customers served within two minutes of ordering with a maximum error of 1.5%