The Konishi Electronics Company manufactures computer microchips. A particular job that has been under analysis as part of a quality-improvement program was the subject of a time study. The time study encompassed 20 job cycles, and the results include the following cumulative times and performance rating factors for each element:

a. Compute the standard time for this job using an allowance factor of 15%.
b. Using a sample standard deviation of 0.51 minutes, determine the number of cycles for this time study such that the company would be 95% confident that the average time from the time study is within 5% of the true average cycletime.

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I(min) 10.52 18.61 26.20 16.46 Element RF 1.15 1.10 1.10 1.05 Time-Stucly Observation Sheet Identification of operation Stein assemby Date 5 Approval Jones Observer Operator Smith usssll Cycles Surmmary Place mug in vise! holder upside domn R 012 205 4.04 5.92 786 980 11.73 13.651564 1759 105 ress both bracket anaie Soider bracket ocam 2 sides around R 019 212 4.09 6.01 7.94 9.80 11.31 13.72 1 15.7 1766 1.00 3 on inside of handlie R 105 3.01 49 687 581 07 126 145616.52 10 Turn stein right side Lp Rİ 1.13 |5.08|493| 6.93|390|10 79|i2.74 | 14.66|16.63|T359 ,J0 Solder ld top to ! bracket R 1.25 376 565 76095 1.45 13.36 15.34 1231 1928 105 Remove stein trom R | 13| | 390 | 5.79丨 7.75 | 9.70 | not 53|15.481 17.461 19.44 1.00