Problem 10-9 After a number of complaints about its directory assistance, a telephone company examined samples of calls to determine the frequency of wrong numbers given to callers. Each sample consisted of 117 calls. SAMPLE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Number of errors 5 3 5 2 3 6 3 2 5 10 3 3 5 3 6 4 a. Determine 95 percent limits. what are the UCL and LCL limits? Solution Sample Errors 5 3 5 2 3 6 3 2 5 10 3 3 5 3 6 4 Average=SUM/16 4.25 Stansard Deviation 2.017 Standard Error=SE=Square Root(SD/n), n=16 0.355 z factor for 95% 1.960 LCL=Mean-SE*z 3.554 UCL=Mean+SE*z 4.946 .