Answer:
The answer is $2,857.14
Explanation:
Let us assume Sales be $500 per month
Monthly
Sales $500
Less: Variable Cost(72%) $360
Contribution(will be 28%) $140
Less: Fixed Cost(Assume) 0
Operating Income $140
If there should be an increase of $800 per month in the operating Income
Revised Operating Income $140 + $800 = $940
Therefore Contribution is equal to $ 940
If Contribution is $940 equal to 28%, then Sales be 100%
$940 ÷ 28%
$3,357.14
Therefore additional increase in Sales revenue required per month
$3,357.14 - $500
$2,857.14