Vertical analysis The condensed income statements through income from operations for Dell Inc. and Apple Inc. for recent fiscal years follow (numbers in millions of dollars):

Dell Inc. Apple Inc.

Sales $56,940 $156,508 Cost of sales 44,754 87,846 Gross profit $12,186 $68,662 Selling, general, and administrative expenses $ 8,102 $10,040 Research and development 1,072 3,381 Operating expenses $ 9,174 $13,421 Income from operations $ 3,012 $55,241 Prepare comparative common-sized statements, rounding percents to one decimal place. Interpret the analyses.