ISDS Chapter 6S Test Questions
with correct Answers
A manager wishes to build a 3 range chart for a process. The sample size is five, the
mean of
sample means is 16.01, and the average range is 5.3. From Table S6.1, the appropriate
value of D3
is 0, and D4 is 2.115. The UCL and LCL for this range chart are: - Answer-11.2 and 0
Plots of sample ranges indicate that the most recent value is below the lower control
limit. What course of action would you recommend? - Answer-Variation is not in control;
investigate what created this condition
To set x -chart upper and lower control limits, one must know the process central line,
which is the: - Answer-average of the sample means
According to the text, the most common choice of limits for control charts is usually: -
Answer-± 3 standard deviations
Which of the following is true of a p-chart? - Answer-The lower control limit may be at
zero
The normal application of a p-chart is in: - Answer-process sampling by attributes
The statistical process chart used to control the number of defects per unit of output is
the: - Answer-c-chart
The c-chart signals whether there has been a: - Answer-change in the number of
defects per unit
The local newspaper receives several complaints per day about typographic errors.
Over a seven day period, the publisher has received calls from readers reporting the
following number of errors: 4, 3, 2, 6, 7, 3, and 9. Based on these data alone, what type
of control chart(s) should the publisher use? - Answer-c-chart
A manufacturer uses statistical process control to control the quality of the firm's
products. Samples of 50 of Product A are taken, and a defective/acceptable decision is
, made on each unit sampled. For Product B, the number of flaws per unit is counted.
What type(s) of control charts should be used? - Answer-p-chart for A, c-chart for B
A nationwide parcel delivery service keeps track of the number of late deliveries (more
than 30 minutes past the time promised to clients) per day. They plan on using a control
chart to plot their results. Which type of control chart(s) would you recommend? -
Answer-c-charts
A run test is used: - Answer-to examine points in a control chart to check for nonrandom
variability
Which of the following is true regarding the process capability index Cpk? - Answer-The
larger the Cpk, the more units meet specifications
If the Cpk index exceeds 1: - Answer-must be less than one-third of the difference
between the specification and the process mean
The statistical definition of Six Sigma allows for 3.4 defects per million. This is achieved
by a Cpk index of: - Answer-2
A Cpk index of 1.00 equates to a defect rate of: - Answer-2.7 per 1,000 items
Acceptance sampling: - Answer-is used to determine whether to accept or reject a lot of
material based on the evaluation of a
sample
Acceptance sampling's primary purpose is to: - Answer-decide if a lot meets
predetermined standards
An acceptance sampling plan's ability to discriminate between low quality lots and high
quality lots is described by: - Answer-an operating characteristics curve
Acceptance sampling: - Answer-a. may involve inspectors taking random samples (or
batches) of finished products and measuring
them against predetermined standards
b. may involve inspectors taking random samples (or batches) of incoming raw
materials and
measuring them against predetermined standards
c. is more economical than 100% inspection
d. may be either of a variable or attribute type, although attribute inspection is more
common in
the business environment
e. All of the above are true.
with correct Answers
A manager wishes to build a 3 range chart for a process. The sample size is five, the
mean of
sample means is 16.01, and the average range is 5.3. From Table S6.1, the appropriate
value of D3
is 0, and D4 is 2.115. The UCL and LCL for this range chart are: - Answer-11.2 and 0
Plots of sample ranges indicate that the most recent value is below the lower control
limit. What course of action would you recommend? - Answer-Variation is not in control;
investigate what created this condition
To set x -chart upper and lower control limits, one must know the process central line,
which is the: - Answer-average of the sample means
According to the text, the most common choice of limits for control charts is usually: -
Answer-± 3 standard deviations
Which of the following is true of a p-chart? - Answer-The lower control limit may be at
zero
The normal application of a p-chart is in: - Answer-process sampling by attributes
The statistical process chart used to control the number of defects per unit of output is
the: - Answer-c-chart
The c-chart signals whether there has been a: - Answer-change in the number of
defects per unit
The local newspaper receives several complaints per day about typographic errors.
Over a seven day period, the publisher has received calls from readers reporting the
following number of errors: 4, 3, 2, 6, 7, 3, and 9. Based on these data alone, what type
of control chart(s) should the publisher use? - Answer-c-chart
A manufacturer uses statistical process control to control the quality of the firm's
products. Samples of 50 of Product A are taken, and a defective/acceptable decision is
, made on each unit sampled. For Product B, the number of flaws per unit is counted.
What type(s) of control charts should be used? - Answer-p-chart for A, c-chart for B
A nationwide parcel delivery service keeps track of the number of late deliveries (more
than 30 minutes past the time promised to clients) per day. They plan on using a control
chart to plot their results. Which type of control chart(s) would you recommend? -
Answer-c-charts
A run test is used: - Answer-to examine points in a control chart to check for nonrandom
variability
Which of the following is true regarding the process capability index Cpk? - Answer-The
larger the Cpk, the more units meet specifications
If the Cpk index exceeds 1: - Answer-must be less than one-third of the difference
between the specification and the process mean
The statistical definition of Six Sigma allows for 3.4 defects per million. This is achieved
by a Cpk index of: - Answer-2
A Cpk index of 1.00 equates to a defect rate of: - Answer-2.7 per 1,000 items
Acceptance sampling: - Answer-is used to determine whether to accept or reject a lot of
material based on the evaluation of a
sample
Acceptance sampling's primary purpose is to: - Answer-decide if a lot meets
predetermined standards
An acceptance sampling plan's ability to discriminate between low quality lots and high
quality lots is described by: - Answer-an operating characteristics curve
Acceptance sampling: - Answer-a. may involve inspectors taking random samples (or
batches) of finished products and measuring
them against predetermined standards
b. may involve inspectors taking random samples (or batches) of incoming raw
materials and
measuring them against predetermined standards
c. is more economical than 100% inspection
d. may be either of a variable or attribute type, although attribute inspection is more
common in
the business environment
e. All of the above are true.
