Homework problem #3-55 has the following linear programming model formulation:

maximize Z = $12x₁ + 8x₂ + 10x₃ + 6x₄ subject to:

flour: 2x₁ + 9x₂ + 1.3x₃ + 2.5x₄ 74 cups

sugar: 2x₁ + .25x₂ + 1x₃ + 1x₄ 24 cups

eggs: 2x₁ + 0x₂ + 5x₃ + 2x₄ 36 eggs

oven: 45x₁ + 35x₂ + 50x₃ + 16x₄ 480 mins

x₁, x₂, x₃, x₄ 0

where x₁ = # cakes, x₂ = # breads, x₃ = #pies and x₄ = #cookies

Here's part of the Sensitivity Report:

What is the maximum amount Tracy should pay for 30 more minutes of oven time?

Here's part of the Sensitivity Report: Constraints Cell Name SH$6 Flour Used SH$7 Sugar Used SH$8 Eggs Used $H$9 Oven time Used Final Value 74 21.4 36 480 Shadow Price 0.08 0.00 1.24 0.21 Constraint Allowable R.H. Side Increase 74 20.37 24 1E+30 36 7.17 480 79.32 Allowable Decrease 26.08 2.60 25.67 79.22