Twenty sets of four measurements of the diameters in inches of Hot Shot golf balls were Sample 1 2.13 2.18 2.05 1.96 2 2.08 2.10 2.02 2.20 3 1.93 1.98 2.03 2.06 4 2.01 1.94 1.91 1.99 5 2.00 1.90 2.14 2.04 6 1.92 1.95 2.02 2.05 7 2.00 1.94 2.00 1.90 8 1.93 2.02 2.04 2.09 9 1.87 2.13 1.90 1.92 10 1.89 2.14 2.16 2.10 11 1.93 1.87 1.94 1.99 12 1.86 1.89 2.07 2.06 13 2.04 2.09 2.03 2.09 14 2.15 2.02 2.11 2.04 15 1.96 1.99 1.94 1.98 16 2.03 2.06 2.09 2.02 17 1.95 1.99 1.87 1.92 18 2.05 2.03 2.06 2.04 19 2.12 2.02 1.97 1.95 20 2.03 2.01 2.04 2.02

a. Enter the data into a spreadsheet and compute the means and the ranges for each sample.

b. Using the results of part (a), develop X and R charts similar to Figures 12–7 and 12–8.

Assume three-sigma limits for the X chart.

c. Develop a histogram based on the 80 observations. Assume class intervals

(1) 1.80–1.849, (2) 1.85–1.899, (3) 1.90–1.949, (4) 1.95–1.999, (5) 2.0–2.049,

(6) 2.05–2.099, (7) 2.10–2.149, (8) 2.15–2.20. Based on your histogram, what distribution might accurately describe the diameter of a golf ball selected at random?