Question

2 10-12) A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds) is too erratic and adversely affects expected profits. The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours. The sample mean and range for each hour are listed below. Hour x R 1 18.4 30 16.9 27 3 14.0 25 21.2. 25 5 21.0 24 33.0 19.3 8 15.8 9 20.0 12 10 14.0 11 Total: 193.6 200 4 6 7 23 18 14 Referring to the table, suppose the supervisor constructs an X chart to see if the process is in-control. What are the lower and upper controllimits of this chart? 12.92, 25.80 8.59, 32.13 19.36 20.90 7.30, 31,42

Answer 1

Page No. Date solution- Heee m=10, n=5 & 7=EXi 193.6 = 19.36 10 R = Eri 209 20.9 10 Uppee f lowee corteal limit of t chast UCL = +AQ = 19.36+0:577(209) :.UCL = 31.42 LCL =7-A2R = 19.36-0.577 (20.9) :.LCL = 7.30 . coddect answee is 7.30, 31.42 value of Ausing factores of contes chaet 357 30 25 UCL a •LCL 5 2 6. 7 10 3 5 8 9 x chatt process 9s not in contool because these lo me point outside the uppere limit of de chart.

Page No. Date Uppee and lowee limit of R chaet UCL= D4 R=(2,114) (20.9) value of Dg f Dy using :.UCL = 44.18 factoes of conteol LCL = D3 R= 0 (209) chast :.LCL-o .. Cooeech answee is 0, 44.18 45 vet 35 30 25. 20 Is to CL OUT 10 2 LCL 01 8 9 & chatt process is en conteol these is no any point outside the conteol limit. . COErect answee ºs Deceeasing teend. ( by using above R chaot