Answer:
1. Degree of operating leverage = [tex]\frac{Contribution}{Net\ Operating\ Income}[/tex]
Contribution = 82,800
Net Operating Income = $61,800
Thus, operating Leverage = [tex]\frac{82,800}{61,800} = 1.339[/tex] = 1.34
2. If Company's sales increase by 13% then contribution also increases by 13%,
Revised Contribution = $82,800 + 13% = $93,564
Revised net Operating income = $93,564 - $21,000 (Fixed Cost) = $72,564
Degree of operating leverage = [tex]\frac{93,564}{72,564} = 1.289[/tex] = 1.29
3. Contribution format income statement:
Sales = $138,000 + 13% = $155,940
Less: Variable Cost 55,200 + 13% = $62,376
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Contribution = $93,564
Less: Fixed Cost = $21,000
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Net Operating Income = $72,564