A bank has freshly taken over the billing function of a company. An agreement specifies that the bank must process 99.2% of the bills in four hours. A study of current process points out that the processing time averages 2.2 hours per bill with the standard deviation of 0.8 hours. A process enhancement team has suggested the change. Experiments point out that the change will lower average processing time to 2 hours, however will increase the standard deviation to 1.2 hours.
a.) With new system, what is probability of processing bills in four hours?
b.) With current system, what is probability of processing the bills in four hours?
c.) Should you change systems?