Question 1

Concluding that a process has changed when it has not is known as a Type I error.

Accepted Answer

A) True 
 B)False

Question 2

Given the following process control data for a quality attribute (three samples of size 400 each):
   If the process proportion of defectives is unknown,what is the estimate of it?

Accepted Answer

The answer of Given the following process control data for...

Question 3

The probability of concluding that an assignable variation exists when only random variation is present is:

Accepted Answer

A) Statistical shift 
B) Specification variation 
C) Control limit error 
D) Type I error 
E) Type II error 
A) Statistical shift 
B) Specification variation 
C) Control limit error 
D) Type I error 
E) Type II error

Question 4

A design engineer wants to construct a sample mean chart for controlling the service life of one of the types of light bulbs his company produces.He knows from numerous previous samples that this service life is normally distributed with a mean of 500 hours and a standard deviation of 20 hours.On three recent production batches,he tested service life on random samples of four bulbs,with these results:   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 5

A Quality Analyst wants to construct a control chart for determining whether four machines,all producing the same product,are under control with regard to a particular quality attribute.Accordingly,she inspected 1,000 units of output from each machine in random samples,with the following results:   If upper and lower control limits were set as 0.028 and 0.010,which machine(s),if any,appear(s)to be out-of-control for process proportion of defectives?

Accepted Answer

A) Machine #3 only 
B) Machine #4 only 
C) Machines #3 and #4 
D) Machines #2 and #3 
A) Machine #3 only 
B) Machine #4 only 
C) Machines #3 and #4 
D) Machines #2 and #3

Question 6

As a rule of thumb,operations with a high proportion of human involvement necessitate less inspection than mechanical operations,which tend to be less reliable.

Accepted Answer

A) True 
 B)False

Question 7

A point which is outside of the lower control limit on an R-chart:

Accepted Answer

A) is an indication that no process variation is present. 
B) should be ignored because it signifies very low process variation. 
C) should be investigated because it could indicate improvements in the methods used in a process. 
D) should be ignored unless another point is outside that limit. 
E) is impossible because the lower limit is always zero. 
A) is an indication that no process variation is present. 
B) should be ignored because it signifies very low process variation. 
C) should be investigated because it could indicate improvements in the methods used in a process. 
D) should be ignored unless another point is outside that limit. 
E) is impossible because the lower limit is always zero.

Question 8

What should managers have in place if a point is observed that is outside the control limits,or a run test produces a large z-value?

Accepted Answer

A) Taking more samples 
B) Revised sample plan 
C) Revisions to the control chart 
D) Recall plans 
E) Response plans 
A) Taking more samples 
B) Revised sample plan 
C) Revisions to the control chart 
D) Recall plans 
E) Response plans

Question 9

Given the following process control data for a quality attribute (three samples of size 400 each):
   If the process is known to produce 11 percent defectives on average,what is the mean of the sampling distribution of sample proportions for whenever this process is under control? The standard deviation?

Accepted Answer

The answer of Given the following process control data for...

Question 10

A Quality Analyst wants to construct a control chart for determining whether three machines,all producing the same product,are under control with regard to a particular quality variable.Accordingly,he sampled four units of output from each machine,with the following results:   What is the sample average range based upon this limited sample?

Accepted Answer

A) 2.0 
B) 4.33 
C) 5.4 
D) 6.0 
E) 9.0 
A) 2.0 
B) 4.33 
C) 5.4 
D) 6.0 
E) 9.0

Question 11

Given the following process control data for a normally distributed quality variable (three samples of size four each):
   If the process is known to have a mean of 15 and a standard deviation of 3,using three sigma control limits,do any of the sample means indicate an out-of-control process mean?

Accepted Answer

No,all are

Question 12

The process capability index,indicated by Cpk is used only when the process is centred.

Accepted Answer

A) True 
 B)False

Question 13

Given the following process control data for a normally distributed quality variable (three samples of size four each):
   If the process is known to have a mean of 15 and a standard deviation of 3,what is the alpha risk (probability of Type I error)for upper and lower control limits of 16.5 and 13.5 respectively? 18 and 12? 19.5 and 10.5?

Accepted Answer

The answer of Given the following process control data for...

Question 14

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 15

The amount of inspection needed is governed by the costs of inspection and the expected costs of passing defective items.

Accepted Answer

A) True 
 B)False

Question 16

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 17

The Chair of the Operations Management Department at Quality University wants to construct a p-chart for determining whether the four instructors teaching the basic P/OM course are under control with regard to the number of students who fail the course.Accordingly,he sampled 100 final grades from last year for each instructor,with the following results:   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 18

The amount of inspection can range from no inspection at all to inspecting each item numerous times.

Accepted Answer

A) True 
 B)False

Question 19

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 20

A control chart used to monitor the fraction of defectives generated by a process 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.

Concluding that a process has changed when it has not is known as a Type I error.

Given the following process control data for a quality attribute (three samples of size 400 each): If the process proportion of defectives is unknown,what is the estimate of it?

The probability of concluding that an assignable variation exists when only random variation is present is:

As a rule of thumb,operations with a high proportion of human involvement necessitate less inspection than mechanical operations,which tend to be less reliable.

A point which is outside of the lower control limit on an R-chart:

What should managers have in place if a point is observed that is outside the control limits,or a run test produces a large z-value?

Given the following process control data for a normally distributed quality variable (three samples of size four each): If the process is known to have a mean of 15 and a standard deviation of 3,using three sigma control limits,do any of the sample means indicate an out-of-control process mean?

The process capability index,indicated by Cpk is used only when the process is centred.

A c-chart is used for:

The amount of inspection needed is governed by the costs of inspection and the expected costs of passing defective items.

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

The amount of inspection can range from no inspection at all to inspecting each item numerous times.

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

A control chart used to monitor the fraction of defectives generated by a process is the:

Introduction to Operations Management

Competitiveness, strategic Planning, and Productivity

Demand Forecasting

Product Design

Reliability

Strategic Capacity Planning

Decision Analysis

Process Design and Facility Layout

Linear Programming

Workjob Design

Learning Curves

Location Planning and Analysis

the Transportation Model

Management of Quality

Acceptance Sampling

Supply Chain Management

Inventory Management

Aggregate Operations Planning and Master Scheduling

Material Requirements Planning and Enterprise Resource Planning

Just-In-Time and Lean Production

Maintenance

Job and Staff Scheduling

Project Management

Waiting-Line Analysis

Simulation

Filters

Exam 15: Statistical Quality Control

Concluding that a process has changed when it has not is known as a Type I error.

Given the following process control data for a quality attribute (three samples of size 400 each): If the process proportion of defectives is unknown,what is the estimate of it?

The probability of concluding that an assignable variation exists when only random variation is present is:

As a rule of thumb,operations with a high proportion of human involvement necessitate less inspection than mechanical operations,which tend to be less reliable.

A point which is outside of the lower control limit on an R-chart:

What should managers have in place if a point is observed that is outside the control limits,or a run test produces a large z-value?

Given the following process control data for a normally distributed quality variable (three samples of size four each): If the process is known to have a mean of 15 and a standard deviation of 3,using three sigma control limits,do any of the sample means indicate an out-of-control process mean?

The process capability index,indicated by Cpk is used only when the process is centred.

A c-chart is used for:

The amount of inspection needed is governed by the costs of inspection and the expected costs of passing defective items.

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

The amount of inspection can range from no inspection at all to inspecting each item numerous times.

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

A control chart used to monitor the fraction of defectives generated by a process is the:

Introduction to Operations Management

Competitiveness, strategic Planning, and Productivity

Demand Forecasting

Product Design

Reliability

Strategic Capacity Planning

Decision Analysis

Process Design and Facility Layout

Linear Programming

Workjob Design

Learning Curves

Location Planning and Analysis

the Transportation Model

Management of Quality

Acceptance Sampling

Supply Chain Management

Inventory Management

Aggregate Operations Planning and Master Scheduling

Material Requirements Planning and Enterprise Resource Planning

Just-In-Time and Lean Production

Maintenance

Job and Staff Scheduling

Project Management

Waiting-Line Analysis

Simulation

Filters