An Automatic Filling Process Is Used to Dispense Hand Sanitizer

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 X-bar chart are ________________________ .

A) 68.48 and 76.52 ml
B) 71.16 and 73.84 ml
C) 70.49 and 74.51 ml
D) 72 and 73 ml
E) None of the above.