A survey of 1,098 online shoppers was conducted. In response to the question of what would influence the shopper to spend more money online for a certain? year, 25?% said free? shipping, 16?% said offering discounts while? shopping, and 14?% said product reviews.
Complete parts a through d below.
a. Construct a 90?% confidence interval estimate of the population proportion π of online shoppers who would be influenced to spend more money online with free shipping.
b. Construct a 90% confidence interval estimate of the population proportion piπ of online shoppers who would be influenced to spend more money online with discounts offered while shopping.
c. Construct a 90% confidence interval estimate of the population proportion π of online shoppers who would be influenced to spend more money online with product reviews.
d. You have been asked to update the results of this study. Determine the sample size necessary to? estimate, with 90% ?confidence, the population proportions in? (a) through? (c) to within ±0.02.