An automatic filling process is used to dispense hand sanitizer into small purse size bottles. The target weight is 75 ml. The company has initiated control charting to stabilize and improve the automatic filling process. For each of twenty-five samples consisting of four bottles, the contents were measured and the mean weight and range were determined. The average of the means across all samples was found to be 72.5 ml. and the average range was 2.75 ml. The control limits for the R chart are
A) 0 and 4.3566 ml
B) 0 and 6.2755 ml
C) 0 and 2.8875 ml
D) 2.00 and 3.50 ml
E) 2.00 and 4.3566 ml

Question

Quizplus · Accepted Answer

The upper control limit (UCL) for the R chart is calculated as R-bar*3.267, where R-bar is the average range. In this case, UCL = 2.75*3.267 = 8.9863 ml. Thus, the control limits for the R chart are 0 and 8.9863 ml. However, the lower limit is always zero by definition. Therefore, the answer is B, which is the only option that includes 0 as the lower limit and 8.9863 ml as the upper limit.

An Automatic Filling Process Is Used to Dispense Hand Sanitizer