The Industrial Engineer undertakes a work sampling on the day-shift maintenance department in a power generating station. The results show that the maintenance operator is idle 18% of the time with an average performance rating of 95%. The total time of the study is 8 hours and total number of machines maintained is 10 units. A. Determine also the required number of samples at 90% confidence level. The confidence interval must be within +0.03 of the true proportion. (z=1.96) Round up in integer number your final answer. B. Determine the normal time of the operator. Use 2 decimal places in your final answer. C. Determine the standard time of the operator if the percentage allowance is 12%. Use 2 decimal places in your final