Samples of three resistors are taken periodically and the

Chapter 10, Problem 3SE

(choose chapter or problem)

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 \(\overline{\overline{X}}=5.095\), \(\overline{R}=0.110\), and (\overline{s}=0.058\).

a. Compute the \(3\sigma\) 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 recompute \(\overline{\overline{X}}\) and \(\overline{R}\).

b. Compute the \(3\sigma\) limits for the \(\overline{X}\) chart. On the basis of the \(3\sigma\) 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?

Equation Transcription:

Text Transcription:

overline{overline{X}}=5.095

overline{R}=0.110

overline{s}=0.058

3{sigma}

overline{overline{X}}

overline{R}

3{sigma}

overline{X}

3{sigma}