(In millions) 2017 $34,397 14,371 2016 2015 Net sales $30,056 13,938 $26,604 Cost of products sold 13,162 Gross margin $20,026 $16,118 $13,442 Required: a. Calculate the gross profit ratio for each of the past three years. (Round your answers to 2 decimal places.) 2017 9% 2016 % 2015 % b. Assume that Campbell's net sales for the first four months of 2018 totaled $12.74 billion. Calculate an estimated cost of goods sold and gross profit for the four months, using the gross profit ratio for 2017 (Round intermediate calculations to 2 decimal places. Enter your answers in millions rounded to nearest wholenumber (i.e.. 5,000,000 should be entered as 5).) Cost of goods sold million Gross profit million