Refer to the following mentioned data. Net sales Cost of products sold Grous margin (In millions) 2017 2016 2015 $34.975 530,401 $26,166 14,031 13.312 13,336 520,944 $17,089 $12,030 Required: a. Calculate the gross profit ratio for each of the past three years. (Round your answers to 2 decimal places.) 2017 2016 2015 50 88 56 211% 4903 b. Assume that Campbell's net sales for the first four months of 2018 totaled $1209 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 whole number (ie, 5,000,000 should be entered as 5).) Cost of goods sold Gross profit million million