Arlington Bank of Commerce and Industry is a busy bank that has requirements for between 10 and 18 tellers depending on the time of day. Lunchtime, from noon to 2 P.M., is usually heaviest. The table below indicates the workers needed at various hours that the bank is open. Time Period Number of Tellers Time Period Number of Tellers Required Required 9 am - 10 am 10 am - 11 am 11 am - Noon Noon -1 pm 1 pm - 2 pm 2 pm - 3 pm 3 pm - 4 pm 4 pm - 5 pm 10 18 12 17 14 15 16 10 The bank now employs 12 full-time tellers, but many people are on its roster of available part-time employees. A part-time employee must put in exactly 4 hours per day but can start anytime between 9 A.M. and 1 P.M. Part-timers are a fairly inexpensive labor pool because no retirement or lunch benefits are provided them. Full-timers, on the other hand, work from 9 A.M. to 5 P.M. but are allowed 1 hour for lunch. (Half the full-timers eat at 11 A.M., the other half at noon.) Fulltimers thus provide 35 hours per week of productive labor time. By corporate policy, the bank limits part-time hours to a maximum of 50% of the day's total requirement. Part-timers earn $6 per hour (or $24 per day) on average, whereas full-timers earn $75 per day in salary and benefits on average. The bank would like to set a schedule that would minimize its total manpower costs. It will release 1 or more of its full-time tellers if it is profitable to do so. a) Formulate this problem as an LP model. ) Solve the problem by Excel. What is the best schedule? What is the total cost for the best schedule?