# Question: Control charts for x and R are maintained for an

Control charts for x and R are maintained for an important quality characteristic. The sample size is n= 7; x and R are computed for each sample. After 35 samples we have found that

(a) Set up x and R charts using these data.

(b) Assuming that both charts exhibit control, estimate the process mean and standard deviation.

(c) If the quality characteristic is normally distributed and if the specifications are 220 35, can the process meet the specifications? Estimate the fraction nonconforming.

(d) Assuming the variance to remain constant, state where the process mean should be located to minimize the fraction nonconforming. What would be the value of the fraction nonconforming under these conditions?

(a) Set up x and R charts using these data.

(b) Assuming that both charts exhibit control, estimate the process mean and standard deviation.

(c) If the quality characteristic is normally distributed and if the specifications are 220 35, can the process meet the specifications? Estimate the fraction nonconforming.

(d) Assuming the variance to remain constant, state where the process mean should be located to minimize the fraction nonconforming. What would be the value of the fraction nonconforming under these conditions?

**View Solution:**## Answer to relevant Questions

Samples of size n = 5 are taken from a manufacturing process every hour. A quality characteristic is measured, and x and R are computed for each sample. After 2 samples have been analyzed, we have The quality characteristic ...An x chart is used to control the mean of a normally distributed quality characteristic. It is known that σ = 6.0 and n = 4. The center line = 200, UCL = 209, and LCL = 191. If the process mean shifts to 188, find the ...Rework Exercises 6.34 and 6.35 using x and s control charts. The process is out of control on the x chart at subgroup 18. After finding assignable cause, exclude subgroup 18 from control limits calculations: Two parts are assembled as shown in Figure 6.28. Assume that the dimensions x and y are normally distributed with means x and y and standard deviations x and y, respectively. The parts are produced on different ...Specifications on a normally distributed dimension are 600 ± 20. x and R charts are maintained on this dimension and have been in control over a long period of time. The parameters of these control charts are as follows (n ...Post your question