Q8 IM13EFinal

This is file Q8IM13E - The fifth of 5 files for solutions to this chapter. This file also includes the solutions to the end-of-chapter cases.

30. Thirty samples of 75 items each were inspected at the Yummy Candy Company and 75 items were found to be defective. Compute control limits for a p-chart for this process.

Ans

30. Control limits for Yummy Candy Company are as follows:

CL = 75/2250 = 0.0333

s = s = = 0.0207

Control limits:

UCLp = + 3 s

UCLp = 0.0333+ 3(0.0207) = 0.0954

LCLp = - 3 s

LCLp = 0.0333 - 3(0.0207) = - 0.0288, use 0

31. Thirty-five samples of 25 orders each at the Bakery Bread, Inc. were inspected, and 25 items were found to be defective. Compute control limits for a p-chart.
Ans.

31. Control limits for Bakery Bread, Inc. orders can be calculated using:

CL = 25/(35)(25) = 25/875 = 0.029

s = s = = 0.034

Control limits:

UCLp = + 3 s UCLp = 0.029 + 3(0.034) = 0.131

LCLp = - 3 s

LCLp = 0.029 - 3(0.034) = - 0.073, use 0

32. Samples of packages orders were taken at the R.A. Treinta Package Co. to determine if the orders were prepared correctly. The percent defectives for each sample are given in the worksheet Prob.13-32 for 25 samples. Five hundred orders are inspected each day for each sample. Construct a p-chart and interpret the results.
Ans.

32. Control limits for the R.A. Treinta Package Co. orders can be calculated using:

CL = 0.012 s = = = 0.0049

Control limits:

UCLp = + 3 sp = 0.012 + 3(0.0049) = 0.0267 LCLp = - 3 sp = 0.012 - 3(0.0049) = - 0.0027 use 0

The process appears to be under control.

33. The fraction defective for a folding process in an Out-of-the-Box plant is given in the worksheet Prob.13-33 for 25 samples. One hundred units are inspected each shift. a. Construct a p-chart and interpret the results. b. After the process was determined to be under control, process monitoring began, using the