.. 10.28 Based on a careful work study in the Hofstetter Corp., the results shown in the following table have been observed: OBSERVATIONS (MINUTES) PERFORMANCE ELEMENT 1 2 3 4 5 RATING (%) Prepare daily reports 35 40 33 42 39 120 Photocopy results 12 10 36a 15 13 110 Label and package reports 3 3 5 5 4 90 Distribute reports 15 18 21 17 45b 85 Photocopying machine broken; included as delay in the allowance factor. bPower outage, included as delay in the allowance factor. 5 a) Compute the normal time for each work element. b) If the allowance for this type of work is 15%, what is the stand- ard time? c) How many observations are needed for a 95% confidence level within 5% accuracy? (Hint: Calculate the sample size of each element.) .. 10.28 Based on a careful work study in the Hofstetter Corp., the results shown in the following table have been observed: OBSERVATIONS (MINUTES) PERFORMANCE ELEMENT 1 2 3 4 5 RATING (%) Prepare daily reports 35 40 33 42 39 120 Photocopy results 12 10 36a 15 13 110 Label and package reports 3 3 5 5 4 90 Distribute reports 15 18 21 17 45b 85 Photocopying machine broken; included as delay in the allowance factor. bPower outage, included as delay in the allowance factor. 5 a) Compute the normal time for each work element. b) If the allowance for this type of work is 15%, what is the stand- ard time? c) How many observations are needed for a 95% confidence level within 5% accuracy? (Hint: Calculate the sample size of each element.)