The net weight (in oz) of a dry desiccant (moisture absorbing product) is to be monitored by x-bar and R control charts using a sample size of n = 5. Data for 20 preliminary samples are as follows.

15.8 16.3 16.2 16.1 16.6
16.3 15.9 15.9 16.2 16.4
16.1 16.2 16.5 16.4 16.3
16.3 16.2 15.9 16.4 16.2
16.1 16.1 16.4 16.5 16.0
16.1 15.8 16.7 16.6 16.4
16.1 16.3 16.5 16.1 16.5
16.2 16.1 16.2 16.1 16.3
16.3 16.2 16.4 16.3 16.5
16.6 16.3 16.4 16.1 16.5
16.2 16.4 15.9 16.3 16.4
15.9 16.6 16.7 16.2 16.5
16.4 16.1 16.6 16.4 16.1
16.5 16.3 16.2 16.3 16.4
16.4 16.1 16.3 16.2 16.2
16.0 16.2 16.3 16.3 16.2
16.4 16.2 16.4 16.3 16.2
16.0 16.2 16.4 16.5 16.1
16.4 16.0 16.3 16.4 16.4
16.4 16.4 16.5 16.0 15.8

(a) Set up x-bar and R control charts using these data. Does the process exhibit statistical control?
(b) Estimate the process mean and standard deviation.
(c) If the specifications are at 16.2 ± 0.5, what conclusions would you draw about process capability?

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