Refer to the following mentioned data. (In millions)

Net sales 2017: $ 34,412 2016: $ 30,135 2015: $ 26,795

Cost of products sold 2017: 14,613 2016: 13,145 2015: 13,236

Gross margin 2017: $ 19,799 2016: $ 16,990 2015: $ 13,559

Required: a. Calculate the gross profit ratio for each of the past three years. (Round your answers to 2 decimal places.)

b. Assume that Campbells net sales for the first four months of 2018 totaled $12.19 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).)