4. Confirm your calculations in Requirement 3 above by increasing the unit sales in your worksheet by 20% so that the Data area looks like this: A B C 1 Chapter 6: Applying Excel 2 3 Data 4 Unit sales 48,000 units 5 Selling price per unit $ 70 per unit 6 Variable expenses per unit $ 28 per unit $ 7 Fixed expenses 1,512,000 (a) What is net operating income? (Negative amount should be indicated by a minus sign.) Net operating income (loss) (b) By what percentage did the net operating income increase? Percentage increase in net operating income %