End-Of-Text Solutions for Chapter 9
9.3 a. quality characteristic b. control chart c. process
9.7 Roughly half the MBNQA point total (450 out of 1000) comes from
Category 7: Results
9.11 The flowchart should have several decision nodes, such as “Is the bank interest rate
competitive?” and “Do the applicants qualify for the amount of the loan?”
9.13 A Pareto chart can be used to display the results.
9.15 Main branches might consist 1. Waiting to be seated, 2. Ordering the meal,
3. Enjoying the meal, and 4. Filing complaints or complements. Secondary
branches can be attached to these main branches.
9.21 Xbar chart: UCL = 449.49; CL = 427.05; LCL = 404.61.
R chart: UCL = 82.23; CL = 38.90; LCL = 0.
9.23 a. UCL = 2.45; CL = 1.32; LCL = 0.18
9.25 a. UCL .0219; CL = .01175; LCL = .0016. b. Observations appear to decrease and
then increase.
9.27 For Northern: UCL = 1454.2; CL = 848.47; LCL = 242.7.
For Southern: UCL = 1551.123; CL = 757.633; LCL = -35.857.
9.29 For Xbar chart: UCL = 24.84; CL = 19.71; LCL = 14.58.
For R chart: UCL = 16.07; CL = 7.04; LCL = 0.
9.31 For Xbar chart: UCL = 10.86; CL = 10.01; LCL = 9.16.
For R chart: UCL = 2.14; CL = 0.83; LCL = 0.
9.35 UCL = .115; CL = .05; LCL = 0.
9.37 a. pbar = .307; UCL = .58; CL = .307; LCL = .03. b. No
9.39 UCL = 6.822; CL = 2.286; LCL = 0.
9.41 For the c chart, UCL = 11.29; CL = 4.75; LCL = 0.
9.43 For the c chart, UCL = 13.578; CL = 6.143; LCL = 0.
b. No, since two plotted values exceed the UCL.
9.47 Process A: Cp = 0.78 (inadequate); Process B: Cp = 1.13
(adequate); Process C: Cp = 2.16 (good); Process D: Cp = 1.11
(adequate)
9.51 a. s' = 7.28; Cpm = 0.97. b. s' = 6.20; Cpm = 1.14.
c. Cpm converges to Cp.
9.53 Process A b. For Process A, Cpk = 1.08; for Process B,
Cpk = 1.22. c. Process B, since it is more capable.
9.55 a. Cp = 1.41 b. Cpk = 1.38
9.63 Since the variation about the target value is expected to
be larger than the usual variance, Cp is usually larger than Cpm.
9.65 The process is considered out of control because the first
six points are increasing and also the sixth observation is above 84.
9.67 a. Scatter diagram b. Flowchart c. Control chart d. Pareto
chart e. Cause-and-effect diagram
9.69 For Xbar chart: UCL = 86.66; CL = 82.475; LCL = 78.286.
For R chart: UCL = 13.123; CL = 5.750; LCL = 0.
9.71 a. c chart b. UCL = 6.14; CL = 1.195; LCL = 0. c. In control.
9.73 a. The xbar chart contains patterns 2, 5, and 6. b. The R chart
gives out of control signals.