Quantitative Analysis for Management, 13/e

Solved Problems

1. Solved Problem 15-1 The manufacturer of precision parts for drill presses produces round shafts for use in the construction of drill presses. The average diameter of a shaft is 0.56 inch. The inspection samples contain six shafts each. The average range of these samples is 0.006 inch. Determine the upper and lower control chart limits.

   Solution

   The mean factor $A_2$ from Table 15.2, where the sample size is six, is seen to be 0.483. With this factor, you can obtain the upper and lower control limits:

   $$\begin{array}{lll}\hfill {\text{UCL}}_{\overline{x}}& =\hfill & 0.56+(0.483)(0.006)\hfill \\ =\hfill & 0.56+0.0029=0.5629\hfill \\ \hfill {\text{LCL}}_{\overline{x}}& =\hfill & 0.56-0.0029\hfill \\ =\hfill & 0.5571\hfill \end{array}$$

2. Solved Problem 15-2 Nocaf Drinks, Inc., a producer of decaffeinated coffee, bottles Nocaf. Each bottle should have a net weight of 4 ounces. The machine that fills ...