Computing and Interpreting Financial Statement Ratios

Following are selected ratios of Norfolk Southern for $2018$ and $2017.$

Return on Assets $($ROA$)$ Component $20182017$

Profitability $($Net income$/$Sales$)27\mathrm{.}3\%55\mathrm{.}2\%$

compute the company$$s ROA for $2018$ and for $2017.$