Answer:
The selling price and variable cost is missing in the question.Therefore it is reproduced here;
Selling Price per unit $190
Variable Expenses $38
Step-by-step explanation:
total sales during the month 1,400*190 $266,000
variable Cost (38+28)*1,400 ($92,400)
Contribution margin $173,600
Fixed Expenses ($87,000)
Net operating income $86,600