operates a metal-parts shop that uses three machines - a drill press, a lathe, and a metal grinder - and all has three operators, each trained and certified to work on all three machines. Each operator performs better on some machines than on others. The shop superintendent has contracted to do a big job that requires all three machines to do the work. The times required by the various machines are summarized as follows: Time per operator per machine: Machine Operator Drill Press Lathe Grinder 1 22 18 35 2 29 30 28 3 25 36 18 The shop superintendent wants to assign one operator to each machine so that the total operating time for all three operators is minimized. Construct the LP and solve the LP model in Excel for this problem.