Consider the following spreadsheet and Excel Solver sensitivity report. (The profit is in dollars, and the variables x1 and x2 represent the number of units of products 1 and 2, respectively.) A B C D E 1 2 Input Information 3 x1 x2 (type) Avail. 4 Constraint 1 2 5 < 42 5 Constraint 2 3 1 < 34 6 Constraint 3 1 1 > 11 7 8 Profit 6 3 9 10 Output Information 11 Variables 12 Profit = Total 13 14 Resources Used Slack/Surplus 15 Constraint 1 16 Constraint 2 17 Constraint 3 18 19 Sensitivity Report Variable Cells Cell Name Final Value Reduced Cost Objective Coefficient Allowable Increase Allowable Decrease $B$11 Variables x1 9.846153846 0 6 3 4.8 $C$11 Variables x2 4.461538462 0 3 12 1 Constraints Cell Name Final Value Shadow Price Constraint R.H. Side Allowable Increase Allowable Decrease $B$15 Constraint 1 Used 42 0.2307692308 42 128 19.333333333 $B$16 Constraint 2 Used 34 1.846153846 34 29 14.333333333 $B$17 Constraint 3 Used 14.30769231 0 11 3.307692308 1E+30 Use the spreadsheet and Excel Solver sensitivity report to answer these questions. (a) What is the cell formula for B12 (the profit contribution of variable x1)? =SUM(B4:B6)*B8 =SUM(B4:B6)*B11 =B8*B11 =B8