The analyst in the Dorben Reference Library decides to use the work sampling technique to establish standards. Twenty employees are involved. The operations include cataloging, charging books out, returning books to their proper location, cleaning books, record keeping, packing books for shipment, and handling correspondence. A preliminary investigation resulted in the estimate that 30 percent of the time of the group was spent in cataloging. How many work sampling observations would be made if it were desirable to be 95 percent confident that the observed data were within a tolerance of ±10 percent of the population data? Describe how the random observations should be made.

The following table illustrates some of the data gathered from 6 of the 20 employees. The number of volumes cataloged equals 14,612. From this data, determine a standard in hours per hundred for cataloging. Then design a control chart based on three-sigma limits for the daily observations.

Operators Vtem Total hours worked Total observations (All elements) Observations involving cataloging Average rating Thomas Apple 80 Smith 78 152 Brown 80 Green Baird 65 72 75 170 181 114 29 143 40 158 45 100 48 50 90 55 90 95 105 85