Problem $10-18($Algo$)$ Return on Investment $($ROI$)$ and Residual Income $[$LO$10-1,$ LO$10-2]$

"I know headquarters wants us to add that new product line," said Dell Havasi, manager of Billings Company's Office Products Division. "But I want to see the numbers before I make any move. Our division's return on investment $($ROI$)$ has led the company for three years, and I don't want any letdown."

Billings Company is a decentralized wholesaler with five autonomous divisions. The divisions are evaluated on the basis of ROI, with year$-$end bonuses given to the divisional managers who have the highest ROIs. Operating results for the company's Office Products Division for this year are given below:

$\backslash$table$[[$Sales$,21,100,{000}^{\text{\$}}$