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Professor Weejohs teaches two sections of business analvtics, which combined will result in 120 final exams to be graded. Professor Weejohs has two assistants, Ralph and Melanie, who will grade the final exams. There is a 3day period between the time the exam is administered and when final grades must be posted. During this period Ralph has 12 hours available and Melanie has 10 hours available to grade the exams. It takes Ralph an average of 12 minutes to grade an exam, and it takes Melanie 12 minutes to grade an exam; however, Ralph's exams will have errors that will require ProfessorWeejohs to ultimately regrade 10% of the exams, while only 6% of Melanie's exams will require regrading. Professor Weejohs wants to know how many exams to assign to each assistant to grade in order to minimize the number of exams to regrade. Solve this model bv using Solver in MS Excel. b. If Professor Weejohs could hire Ralph or Melanie to work 1 additional hour, which should he choose? What would be the effect of hiring the selected assistant for 1 additional hour