please explain, thank you

Differential Analysis for Sales Promotion Proposal Sole Mates Inc. is planning a one-month campaign for July to promote sales of one of its two shoe products. A total of $126,000 has been budgeted for advertising, contests, redeemable coupons, and other promotional activities. The following data have been assembled for their possible usefulness in deciding which of the products to select for the campaign: Tennis Walking Shoes Shoes Unit selling price $69 $76 Unit production costs: Direct materials $(12) $(16) Direct labor (4) (5) Variable factory overhead i (3) (4) Fixed factory overhead (7) (9) Total unit production costs $(26) $(34) Unit variable selling expenses (22) (20) Unit fixed selling expenses (12) (8) Total unit costs $(60) $(62) $9 $14 Operating income per unit No increase in facilities would be necessary to produce and sell the increased output. It is anticipated that 20,000 additional units of tennis shoes or 17,000 additional units of walking shoes could be sold without changing the unit selling price of either product. Required: zero, enter 1. Prepare a differential analysis as of June 19 to determine whether to promote tennis shoes (Alternative 1) or walking shoes (Alternative 2). If an amount i "0". Use a minus sign to indicate costs. If required, use a minus sign to indicate a loss. Differential Analysis Promote Tennis Shoes (Alt. 1) or Promote Walking Shoes (Alt. 2) 1. Prepare a differential analysis as of June 19 to determine whether to promote tennis shoes (Alternative 1) or walking shoes (Alternative 2). If an amount is zero, enter "0". Use a minus sign to indicate costs. If required, use a minus sign to indicate a loss. Differential Analysis Promote Tennis Shoes (Alt. 1) or Promote Walking Shoes (Alt. 2) June 19 Promote Promote Differential Tennis Shoes Walking Shoes Effects (Alternative 1) (Alternative 2) (Alternative 2) Revenues Costs: Direct materials Direct labor Variable factory overhead Variable selling expenses Sales promotion Profit (loss) 2. Determine whether to promote tennis shoes (Alternative 1) or walking shoes (Alternative 2). 3. The sales manager had tentatively decided to promote walking shoes, estimating that operating income would be increased by $112,000 ($14 operating income per unit for 17,000 units, less promotion expenses of $126,000). The manager also believed that the selection of tennis shoes would reduce operating income by, $54,000 ($9 operating income per unit for 20,000 units, less promotion expenses of $126,000). State briefly your reasons for supporting or opposing the tentative decision. considered the full unit costs instead of the The sales manager, The sales manager's tentative decision should be differential (additional) revenue and differential (additional) costs. An analysis similar to that presented in part (1) would lead to the selection of to operating income than would be contributed by promoting for the promotional campaign, because this alternative will contribute