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 cycle time.

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Element ΣΤ (min) RF 10.52 1 1.15 18.61 1.10 26.20 1.10 4 16.46 1.05 Time-Study Observation Sheet Identification of operation Stein aeaembly Date 715 Operator Luong Approval Observer Patel Ruaael Cycles Summary 10 RF Ne Place mug in viaer holder upside doun Ra12 205 4.04 5.92 786s 980 1.75 13.e 5.64 17.59 105 Press both bracket 2 siden around handle RO.19 2z 4.096.0 z94 988 1181 13.72 15.7 17.66 1.00 Solder racket seam on ineide of hande R105 3.01 4.9 6.87 881 10.71 12.66 14.56 1652 1850 110 Turn stein right olde RL.13 3.08 4.98 6.93 89o T0.79 12.74 14.e T6.6 1859 Solder lad top to 5bracket R 175 3.785.65 7.60 956 1.45 13.36 15.34 17.31 1928 105 Romove stain from holder and place in box R 191 3.90|5.79 775 9.70 11.61 3.6915.49 17.46 1944 100 6.