Samples of four units were taken from the engine manufacturing process. The weight of engine was measured (in lbs), and average and range was calculated for each sample. After 25 samples, the following results were calculated as per the table shown below. All points on the X and R charts fell in the control limits. The specification limits for the weight of the engine are 823 17 lbs. If the weight is normally distributed and distribution is centered at X , what percentage of product would you expect to fall outside of specification limits?
Averages Ranges
Upper control limit 844 72.6
center line 826.5 36.2
lower control limit 809 0