Answer to Question #318041 in Statistics and Probability for Kirti

Question

A cricket ball manufacturing company wants to check the variation in the

weight of the balls. For this, 25 samples each of size 4, are selected and the weight of

each ball is measured (in grams). The sum of the sample averages and the sum of 25

sample ranges were found to be ∑ 𝑥′𝑖

25

𝑖=1 = 4010

grams and ∑ 𝑅𝑖 25

𝑖=1 = 72 grams, respectively.

Compute the control limits for the X’ and R-charts. It is given that A2 = 0.729, D3 = 0 and

D4 = 2.282.