2. Data from a sample of 5 pharmacies are used to examine the relation between prescription sales volume and the percent of prescription ingredients purchase directly from the suppliers. The sample data are shown here: Sales Volume, y % of Ingredients (in $1,000) Purchased Directly, x xy y x-square 25 10 250 625 100 SS 18 990 3,025 324 50 25 1,250 2,500 625 T5 40 3,000 5,625 1,600 110 50 5,500 1,2100 2,500 Total 315 143 10,990 23,375 5,149