The Dubuque Cement Company packs 80-pound bags of concrete mix. Time-study data for the filling activity are shown in the following table. Because of the high physical demands of the job, the company’s policy is a 23% allowance for workers.

a) Compute the standard time for the bag-packing task.

b) How many observations are necessary for 99% confidence, within {5% accuracy?

ELEMENT OBSERVATIONS (SECONDS) PERFORMANCE 1 2 3 4 5 RATING (%)

Grasp and place bag 8 9 8 11 7 110 Fill bag 36 41 39 35 112a 85 Seal bag 15 17 13 20 18 105 Place bag on conveyor 8 6 9 30b 35b 90 a

Bag breaks open; included as delay in the allowance factor.

b Conveyor jams; included as delay in the allowance factor.