Seved Kefer to the following mentioned data. Net sales cost of products sold Gross margin (In millions) 2017 2016 2015 $34,672 $30,234 $26,265 14,329 13, 770 13,853 $20,343 $16,464 $12,412 Required: a. Calculate the gross profit ratio for each of the past three years. (Round your answers to 2 decimal places.) 2017 2016 2015 58.67% 54.46 % 47.26 % b. Assume that Campbell's net sales for the first four months of 2018 totaled $12.24 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 (i.e., 5,000,000 should be entered as 5.) Cost of goods sold Gross profit million million