The service division of Monty Industries reported the following results for $2025.$

Sales

$$490,000$

Variable costs

$294,000$

Controllable fixed costs

$73,500$

Average operating assets

$612,500$

Management is considering the following independent courses of action in $2026$ in order to maximize the return on investment for this division.

Reduce average operating assets by $$122,500,$ with no change in controllable margin.

Increase sales $$98,000,$ with no change in the contribution margin percentage.

$($a$)$

Compute the controllable margin and the return on investment for $2025.$