Please help Urgent!

The following linear program determines how many necklaces (X1), bracelets (X2), rings (X3), and earrings (X4) a jewelry store should stock. The objective function measures profit; it is assumed that every piece stocked will be sold. Constraint 1 measures display space in units, constraint 2 measures time to set up the display in minutes. Constraints 3 and 4 are marketing restrictions.

LINEAR PROGRAMMING PROBLEM

MAX 100X1+120X2+150X3+125X4

S.T.

1) X1+2X2+2X3+2X4

2) 3X1+5X2+X4

3) X1+X3

4) X2+X3+X4>50

Here is the answer report:

Problem (Part 1):

How many rings should be stocked?

Problem (Part 2):

To what value can the profit on necklaces drop before the solution would change?

(Part 3):

You are offered the chance to obtain more space. The offer is for 15 units and the total price is 1500. What should you do?

Here is the answer report: Objective Cell (Max) Cell Name $B$9 Total Profit Original Value 495 Final Value 7475 Original Value 1 Variable Cells Cell Name $B$4 Necklaces $B$5 Bracelets $B$6 Rings $B$7 Earrings 1 Final Value Integer 8 Contin O Contin 17 Contin 33 Contin 1 1 Slack Constraints Cell Name $B$13 Display Space LHS $B$14 Time LHS $B$15 Marketing 1 LHS $B$16 Marketing 2 LHS Cell Value Formula Status 108 $B$13=$D$16 Binding 0 63 0 0 And here is the sensitivity report: Variable Cells 12.5 Cell Name $B$4 Necklaces $B$5 Bracelets $B$6 Rings $B$7 Earrings Final Reduced Objective Allowable Allowable Value Cost Coefficient Increase Decrease 8 0 100 1E+30 0 -5 120 5 1E+30 17 0 150 12.5 25 33 0 125 25 5 Constraints Cell Name $B$13 Display Space LHS $B$14 Time LHS $B$15 Marketing 1 LHS $B$16 Marketing 2 LHS Final Shadow Constraint Allowable Allowable Value Price R.H. Side Increase Decrease 108 75 108 15.75 8 57 0 120 1E+30 63 25 25 25 33 17 50 -25 50 4 8.5