15. National Presto is a manufacturer of small electrical appliances and housewares, including pressure cookers, heaters, canners, fry pans, griddles, roaster ovens, deep fryers, corn poppers, can openers, coffee makers, slicers, hand mixers, and portable ranges. Its quarterly sales in millions of dollars for several years are shown in Table P-15. Presto does most of its business at Christmas, so there is a strong seasonal effect. Develop a multiple regression model using dummy variables to forecast sales for the third and fourth quarters of 1996. Write a report summarizing your results.