Samples of three resistors are taken periodically, and the resistances, in ohms, are measured. The following table presents the means, ranges, and standard deviations for 30 consecutive samples.

The means are = 5.095, = 0.110, and = 0.058.
a. Compute the 3σ limits for the R chart. Is the variance out of control at any point? If so, delete the samples that are out of control and recomputed and.
b. Compute the 3σ limits for the chart. On the basis of the 3σ limits, is the process mean in control? If not, at what point is it first detected to be out of control?
c. On the basis of the Western Electric rules, is the process mean in control? If not, when is it first detected to be out of control?

Transcribed Image Text:

751197' 9 3 5 4 6 5 1 2 2 8 7 1 2 5 4 1 4 6782466 s-0000000000000 68782089, 7 4 1 5 2 3 3 3 1 82 4555731 110110101101110011010001011101 11 4 2 9 7 2 2 2 2 5 6 2 4 9 7 2 4 0 0 0 6 3 9 9 9 00 02 07 03 06 1 12100 555555555555555555554544455555 mp 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 20 21 22 23 24 25 26 27 2 2 3 890 11122