Determine upper and lower control limits

1. The overall average on a process you are attempting to monitor is 49 units. The process standard deviation is 1.52. Determine the upper and lower control limits for a mean chart, if you choose to use a sample size of 5. Set z=3.

UCLx = ____________
LCLx = ____________

Round your answers to 2 decimal places; for example, 12.34 .

2. Thirty-five samples of size 7 each were taken from a fertilizer-bag-filling machine. The results were: Overall mean = 66.25 lb.; Average range = 1.69 lb. Show work if possible.

Determine the upper and lower control limits of the  X bar-chart with z=3 .

UCL=____________
LCL=____________
Round your answers to 2 decimal places; for example, 12.34 .
Determine the upper and lower control limits of the R-chart with z=3 .

UCL=____________
LCL=____________
Round your answers to 2 decimal places; for example, 1.23 .

Attached file(s):

Upper and lower control limits.doc  View File