Where the above conditions are given, it is to be noted that the return on incremental investment is about 45.93%
When you want to compute the return on incremental invesment, you have to first consider the incremental net income. When you have established that, you can now divide it by the increamental invesment.
Step 1 - compute the increament in sales:
$486,000 x (1- uncollectible percentage)
= 486,000 x (1-0.12)
= 427,680
Scondly step is to compute the increamental expnse of collection
This is already given as $17,800
Thirdly, derive the incremntal Gross profit
$427,680 x (1-0.75)
=106 920
Fourth step is to compute the incremental net income (before taxation):
$106,920 - $17,800
= $89,120
Fifth step is to compute the incremental net income (after taxation)
$89,120 x (1-Tax Rate)
= $89,120 x (1-0.35)
= $57,848
Now we compute the return on incremntal invesment which is given as:
[Incremental Net Income/Incremental Investment] x (360/average collection period)
= (57,848/(486,000+17,800)) x (360/90)
= 0.11482334259 x 4
= 0.45929337036
Convert to percentage and we'll get:
=0.45929337036 x 100
= 45.929337036%
≈ 45.93%
Hence, it is correct to state that the return on incremental investment is about 45.93%.