A time study analyst has collected 10 readings on a particular work element of interest and would like to consider how many more cycles to time. Based on the sample, the mean time for the element is 0.65 min and the sample standard deviation s is 0.10 min.

a) At a 95% confidence level, how many cycles should be timed to ensure the actual element time is within 8% of the mean?

b) If there is no time to observe more cycles, determine the size of the confidence interval at confidence level 95%.

c) Given the following from-between chart indicating the flow among 5 departments, you are asked to find placement orders of these departments.

(please solve all)