Question 1

A point that plots below the lower control limit on the range chart:

Accepted Answer

A) should be ignored because lower variation is desirable. 
B) should be investigated for random variation. 
C) may be an indication that process variation has decreased 
D) is not possible 
E) is due to a shift in the process mean 
A) should be ignored because lower variation is desirable. 
B) should be investigated for random variation. 
C) may be an indication that process variation has decreased 
D) is not possible 
E) is due to a shift in the process mean

Question 2

The six sigma quality improvement methodology is called:

Accepted Answer

A) PDSA 
B) DMAIC 
C) 5W2H 
D) continuous improvement system. 
A) PDSA 
B) DMAIC 
C) 5W2H 
D) continuous improvement system.

Question 3

The optimum level of inspection occurs when the cost of passing defectives is minimized.

Accepted Answer

A) True 
 B)False

Question 4

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

Accepted Answer

A) True 
 B)False

Question 5

As the sample size increases,the distribution of sample averages approaches a Normal distribution regardless of the shape of the sampled population.This is identified in which of the following?

Accepted Answer

A) Assignable variation 
B) Random variation 
C) Central limit theorem 
D) Type I errors 
E) Mean charts 
A) Assignable variation 
B) Random variation 
C) Central limit theorem 
D) Type I errors 
E) Mean charts

Question 6

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 is the sample mean service life for sample 2?

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 7

The process capability index,indicated by Cp is calculated as the ratio of the design specification width to the process width.

Accepted Answer

A) True 
 B)False

Question 8

The sampling distribution of sample means taken from a process has less variability than the distribution of the process.

Accepted Answer

A) True 
 B)False

Question 9

A control chart used to monitor the process mean 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 10

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 11

The specification limits for a product are 8 cm and 10 cm.A process that produces the product has a mean of 9.5 cm and a standard deviation of 0.2 cm.What is the process capability,Cpk?

Accepted Answer

A) 3.33 
B) 1.67 
C) 0.83 
D) 2.50 
A) 3.33 
B) 1.67 
C) 0.83 
D) 2.50

Question 12

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:   Using the factors for three sigma control limits,what are the sample range (R)chart upper and lower control limits?

Accepted Answer

A) 11.14 and 0 
B) 9.88 and 0 
C) 8.66 and 0 
D) 4.94 and 0 
E) 4.33 and 0 
A) 11.14 and 0 
B) 9.88 and 0 
C) 8.66 and 0 
D) 4.94 and 0 
E) 4.33 and 0

Question 13

Appraisal of a good or service against a standard is called inspection.

Accepted Answer

A) True 
 B)False

Question 14

Control limits are determined based on design specification limits.

Accepted Answer

A) True 
 B)False

Question 15

For which of the following would a p-chart be used?

Accepted Answer

A) Monitor the process means for samples. 
B) Monitor dispersion in sample data. 
C) Monitor the proportion of defectives in a sample. 
D) Monitor the number of defects per unit. 
E) Monitor the range of values in samples. 
A) Monitor the process means for samples. 
B) Monitor dispersion in sample data. 
C) Monitor the proportion of defectives in a sample. 
D) Monitor the number of defects per unit. 
E) Monitor the range of values in samples.

Question 16

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 is the estimate of the standard deviation of the sampling distribution for an instructor's sample proportion of failures?

Accepted Answer

A) .0075 
B) .03 
C) .075 
D) .3 
E) .75 
A) .0075 
B) .03 
C) .075 
D) .3 
E) .75

Question 17

A process capability index (Cp)of 0.70 indicates that a process is capable of producing to design specifications.

Accepted Answer

A) True 
 B)False

Question 18

Too many observations on one side of the centre line on a run chart is an indication of what?

Accepted Answer

A) cycles 
B) trend 
C) bias 
D) level shift 
E) too much dispersion 
A) cycles 
B) trend 
C) bias 
D) level shift 
E) too much dispersion

Question 19

Control limits are statistical limits that reflect the extent to which sample statistics such as means and ranges can vary due to random variation alone.

Accepted Answer

A) True 
 B)False

Question 20

Approximately 99.7% of sample means will fall within $\pm$two standard deviations of the process mean.

Accepted Answer

A) True 
 B)False

Exam 15: Statistical Quality Control

A point that plots below the lower control limit on the range chart:

The six sigma quality improvement methodology is called:

The optimum level of inspection occurs when the cost of passing defectives is minimized.

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

As the sample size increases,the distribution of sample averages approaches a Normal distribution regardless of the shape of the sampled population.This is identified in which of the following?

The process capability index,indicated by Cp is calculated as the ratio of the design specification width to the process width.

The sampling distribution of sample means taken from a process has less variability than the distribution of the process.

A control chart used to monitor the process mean is the:

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

The specification limits for a product are 8 cm and 10 cm.A process that produces the product has a mean of 9.5 cm and a standard deviation of 0.2 cm.What is the process capability,Cpk?

Appraisal of a good or service against a standard is called inspection.

Control limits are determined based on design specification limits.

For which of the following would a p-chart be used?

A process capability index (Cp)of 0.70 indicates that a process is capable of producing to design specifications.

Too many observations on one side of the centre line on a run chart is an indication of what?

Control limits are statistical limits that reflect the extent to which sample statistics such as means and ranges can vary due to random variation alone.

Approximately 99.7% of sample means will fall within ±\pm± two standard deviations of the process mean.

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

A process capability index (C_p)of 0.70 indicates that a process is capable of producing to design specifications.

Approximately 99.7% of sample means will fall within $\pm$ two standard deviations of the process mean.