A market research consultant hired by a leading soft-drink company is interested in estimating the difference between the proportions of female and male consumers who favor the company’s low-calorie brand over the leading competitor’s low-calorie brand in a particular geographical region. A random sample of 250 consumers from the market under investigation is provided in the file P08_18.xlsx. After separating the 250 randomly selected consumers by gender, find a 95% confidence interval for the difference between these two proportions. Of what value might this interval estimate be to marketing managers at the company?