Case 9-3 Vertical analysis The condensed income statements through income from operations for Apple Inc. and Dell Inc. are reproduced below for recent fiscal years (numbers in millions of dollars). Apple Inc. Dell Inc. Sales (net) $156,508 $62,071 Cost of sales 87,846 48,260 Gross profit $ 68,662 $13,811 Selling, general, and administrative expenses $ 10,040 $ 8,524 Research and development expenses 3,381 856 Operating expenses $ 13,421 $ 9,380 Income from operations $ 55,241 $ 4,431 Prepare comparative common-sized statements, rounding percents to one decimal place. Interpret the analyses.