Computing, Analyzing, and Interpreting Return on Equity and Return on AssetsFollowing are summary nancial statement data for Nordstrom Inc. for scal years ended 2014 through 2016.$ millions 2016 2015 2014Sales. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $14,095 $13,110 $12,166Net income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 720 734Total assets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,698 9,245 8,574Equity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 871 2,440 2,080Required

a. Compute return on assets and return on equity for fiscal years ended 2015 and 2016 (use average assets and average equity), together with the components of ROA (profit margin and asset turnover). What trends, if any, do we observe?

b. Which component, if any, appears to be driving the change in ROA over this time period?