Create X-bar and R charts.
-A company that manufactures health food snacks produces low sodium rice chips. To
Monitor the process for sodium levels, chips are selected periodically and the amount of
Sodium (mg) measured. For each of thirty samples consisting of 8 chips, the mean and
Range in sodium content is determined. The average of the means across all samples is 55
Mg and the average range is 2.2 mg. The lower and upper control limits for the R chart
Are
A) 0.2992 and 4.1008 mg.
B) 0 and 4.4088 mg.
C) 0.136 and 1.864 mg.
D) 2.1999 and 30.152 mg.
E) 0.2493 and 3.4167 mg.

Question

Quizplus · Accepted Answer

The correct answer is A because the lower and upper control limits for the R chart are calculated as follows:Lower control limit (LCL) = D3 * Rbar = 0 * 2.2 = 0 mgUpper control limit (UCL) = D4 * Rbar = 2.282 * 2.2 = 4.1008 mg

Create X-Bar and R Charts