Standard Deviation Mean Observed Time Work Element (minutes) (minutes) Performance Rating 1 1.2 22.2 1.1 2 0.9 31.2 1.4 3 1.3 44.4 0.6 4 0.6 13.6 1.2 5 0.4 22.8 0.9 (a) Determine the sample size needed if the standard time estimate is to be within 2% of the true mean 99% of the time. (b) Calculate the normal time for each work element. (c) Using an allowance factor of 20% based on the amount of time worked, calculate the standard time for each work element and for the entire job. (d) Based on the standard time, how many units should an employee performing at 110% of standard complete during an 8-hour day