Selected data from the September 26,2020 , and September 28,2019 , consolidated balance sheets and income statements (statements of operations) for the years then ended for Apple Incorporated follow. All amounts are reported in millions. Required: a. Calculate the amount of Apple's gross profit for each year. Has gross profit as a percentage of sales changed significantly during the past year? b. Calculate the amount of Apple's operating income for each year. Has operating income as a percentage of sales changed significantly during the past year? c. After completing requirements a and b, calculate the other missing amounts for each year. Complete this question by entering your answers in the tabs below. After completing requirements a and b, calculate the other missing amounts for each year. Note: Enter decreases with a minus sign to indicate a negative financial statement effect. Enter your answer in millions of dollars