Question 1

What are the .95 (5% alpha risk)upper and lower control limits for the p-chart?

Accepted Answer

A)  .95 and .05 
B)  .13 and .07 
C)  .1588 and .0412 
D)  .16 and .04 
E)  .1774 and .0226 
A)  .95 and .05 
B)  .13 and .07 
C)  .1588 and .0412 
D)  .16 and .04 
E)  .1774 and .0226

Question 2

If a point on a control chart falls outside one of the control limits,this suggests that the process output is non-random,assignable variation.

Accepted Answer

A) True 
 B)False

Question 3

Using three sigma control limits (rather than two sigma limits)tends to have what impact on error probabilities?

Accepted Answer

A)  Increase the Type II and decrease the Type I. 
B)  Decrease the Type II and increase the Type I. 
C)  Decrease the Type I and Type II. 
D)  Increase the Type I and Type II. 
E)  Have little or no impact. 
A)  Increase the Type II and decrease the Type I. 
B)  Decrease the Type II and increase the Type I. 
C)  Decrease the Type I and Type II. 
D)  Increase the Type I and Type II. 
E)  Have little or no impact.

Question 4

The number of defective parts in a sample is a process characteristic that is counted rather than measured.

Accepted Answer

A) True 
 B)False

Question 5

A point that plots below the lower control limit on the range chart:
I.should be ignored because lower variation is desirable.
II.may be an indication that process variation has decreased.
III.should be investigated for assignable cause.

Accepted Answer

A)  I and II 
B)  I and III 
C)  II and III 
D)  II only 
E)  I, II, and III 
A)  I and II 
B)  I and III 
C)  II and III 
D)  II only 
E)  I, II, and III

Question 6

What is the sample proportion of failures for Prof.D?

Accepted Answer

A)  0 
B)  .04 
C)  .11 
D)  .13 
E)  .16 
A)  0 
B)  .04 
C)  .11 
D)  .13 
E)  .16

Question 7

What value should be used as the mean of the sampling distribution of sample means?

Accepted Answer

A)  19 ounces 
B)  20 ounces 
C)  20.6 ounces 
D)  21 ounces 
E)  23 ounces 
A)  19 ounces 
B)  20 ounces 
C)  20.6 ounces 
D)  21 ounces 
E)  23 ounces

Question 8

Variation in a sample statistic collected from a process may be either random variation or assignable variation.

Accepted Answer

A) True 
 B)False

Question 9

What is the estimate of the process mean based on this limited number of samples?

Accepted Answer

A)  16 
B)  19 
C)  20 
D)  21 
E)  23 
A)  16 
B)  19 
C)  20 
D)  21 
E)  23

Question 10

A sample statistic that falls outside the control limits suggests that the process mean has changed.

Accepted Answer

A) True 
 B)False

Question 11

Studies on a machine that molds plastic water pipe indicate that when it is injecting 25 mm diameter pipe,the process standard deviation is 0.50 mm.The 25 mm pipe has a specification of 25 mm plus or minus 1.0 mm.What is the process capability index (Cp)?

Accepted Answer

A)  0.50 
B)  0.67 
C)  1.00 
D)  2.00 
E)  None of the choices are correct. 
A)  0.50 
B)  0.67 
C)  1.00 
D)  2.00 
E)  None of the choices are correct.

Question 12

What value should be used as the mean of the sampling distribution of sample means?

Accepted Answer

A)  470 hours 
B)  495 hours 
C)  500 hours 
D)  515 hours 
E)  525 hours 
A)  470 hours 
B)  495 hours 
C)  500 hours 
D)  515 hours 
E)  525 hours

Question 13

The primary purpose of statistical process control is to detect defects in finished products before they are shipped to customers.

Accepted Answer

A) True 
 B)False

Question 14

The DMAIC methodology involves all EXCEPT which of the following?

Accepted Answer

A)  Define 
B)  Model 
C)  Analyze 
D)  Improve 
E)  Control 
A)  Define 
B)  Model 
C)  Analyze 
D)  Improve 
E)  Control

Question 15

Using the factors for three sigma control limits,what are the x-bar chart upper and lower control limits?

Accepted Answer

A)  24.33 and 15.67 
B)  23.29 and 16.71 
C)  23.5 and 16.5 
D)  23.16 and 16.84 
E)  24.42 and 17.67 
A)  24.33 and 15.67 
B)  23.29 and 16.71 
C)  23.5 and 16.5 
D)  23.16 and 16.84 
E)  24.42 and 17.67

Question 16

A process is "capable" if the process output falls within the design specification.

Accepted Answer

A) True 
 B)False

Question 17

A control chart used to monitor the number of defects per unit is the:

Accepted Answer

A)  p-chart. 
B)  R-chart. 
C)  x-bar chart. 
D)  c-chart. 
E)  Gantt chart. 
A)  p-chart. 
B)  R-chart. 
C)  x-bar chart. 
D)  c-chart. 
E)  Gantt chart.

Question 18

A c-chart is used for:

Accepted Answer

A)  means. 
B)  ranges. 
C)  percent defective. 
D)  fraction defective per unit. 
E)  number of defects per unit. 
A)  means. 
B)  ranges. 
C)  percent defective. 
D)  fraction defective per unit. 
E)  number of defects per unit.

Question 19

The sample size chosen for control charts depends on the cost of inspection versus the expected cost of Type II error.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following is not needed to calculate sample mean control charts?

Accepted Answer

A)  A choice for z, the standard normal deviate (usually 2 or 3). 
B)  The standard deviation of the sampling distribution. 
C)  The sample range. 
D)  The average of sample means (grand mean). 
A)  A choice for z, the standard normal deviate (usually 2 or 3). 
B)  The standard deviation of the sampling distribution. 
C)  The sample range. 
D)  The average of sample means (grand mean).

Exam 10: A: Statistical Quality Control

What are the .95 (5% alpha risk)upper and lower control limits for the p-chart?

If a point on a control chart falls outside one of the control limits,this suggests that the process output is non-random,assignable variation.

Using three sigma control limits (rather than two sigma limits)tends to have what impact on error probabilities?

The number of defective parts in a sample is a process characteristic that is counted rather than measured.

A point that plots below the lower control limit on the range chart: I.should be ignored because lower variation is desirable. II.may be an indication that process variation has decreased. III.should be investigated for assignable cause.

What is the sample proportion of failures for Prof.D?

What value should be used as the mean of the sampling distribution of sample means?

Variation in a sample statistic collected from a process may be either random variation or assignable variation.

What is the estimate of the process mean based on this limited number of samples?

A sample statistic that falls outside the control limits suggests that the process mean has changed.

Studies on a machine that molds plastic water pipe indicate that when it is injecting 25 mm diameter pipe,the process standard deviation is 0.50 mm.The 25 mm pipe has a specification of 25 mm plus or minus 1.0 mm.What is the process capability index (Cp)?

What value should be used as the mean of the sampling distribution of sample means?

The primary purpose of statistical process control is to detect defects in finished products before they are shipped to customers.

The DMAIC methodology involves all EXCEPT which of the following?

Using the factors for three sigma control limits,what are the x-bar chart upper and lower control limits?

A process is "capable" if the process output falls within the design specification.

A control chart used to monitor the number of defects per unit is the:

A c-chart is used for:

The sample size chosen for control charts depends on the cost of inspection versus the expected cost of Type II error.

Which of the following is not needed to calculate sample mean control charts?

Introduction to Operations Management

Competitiveness, Strategic Planning, and Productivity

Demand Forecasting

A: Product Design

B: Product Design

A: Strategic Capacity Planning

B: Strategic Capacity Planning

A: Process Design and Facility Layout

B: Process Design and Facility Layout

A: Design of Work Systems

B: Design of Work Systems

A: Location Planning and Analysis

B: Location Planning and Analysis

Management of Quality

B: Statistical Quality Control

Supply Chain Management

Inventory Management

Aggregate Operations Planning

Material Requirements Planning and Enterprise Resource Planning

A: Just-In-Time and Lean Production

B: Just-In-Time and Lean Production

Job and Staff Scheduling

Project Management

A: Waiting-Line Analysis

B: Waiting-Line Analysis

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