Each hour from 10 A.M. to 7 P.M., Bank One receives checks and must process them. Its goal is to process all checks the same day they are received. The bank has 13 check processing machines, each of which can process up to 500 checks per hour. It takes one worker to operate each machine. Bank One hires both full-time and part-time workers. Full-time workers work 10 A.M. to 6 P.M., 11 A.M. to 7 P.M., or 12 P.M. to 8 P.M. and are paid $160 per day. Part-time workers work either 2 P.M. to 7 P.M. or 3 P.M. to 8 P.M.

and are paid $75 per day. The numbers of checks received each hour are listed in the file P04_114.xlsx.

In the interest of maintaining continuity, Bank One believes that it must have at least 3 full-time workers under contract. Develop a work schedule that processes all checks by 8 P.M. and minimizes daily labor costs.