Explore BrainMass
Share

# Upper and lower control limits for /x- and R-charts

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

Find the upper and lower control limits for /x- and R-charts for the width of a chair seat when the sample grand mean (based on 30 samples of 6 observations each) is 27.0 inches, and the average range is 0.35 inches.

https://brainmass.com/math/calculus-and-analysis/upper-and-lower-control-limits-for-x-and-r-charts-170261

#### Solution Preview

Since sample size= 6
A2= 0.48
D3= 0
D4= 2.00

Mean of ...

\$2.19

## 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 = ____________

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=____________