• S6.3 Thirty-five samples of size 7 each were taken from a fertilizer-bag-filling machine at Panos Kouvelis Lifelong Lawn Ltd.

The results were overall mean = 57.75 lb; average range = 1.78 lb.

a) Determine the upper and lower control limits of the x-chart, where s = 3.

b) Determine the upper and lower control limits of the R-chart, where s = 3.