Homework Help is Here – Start Your Trial Now!
Math
Statistics
Each day, an electronics manufacturer creates thousands of small fan motors for computers. The speed (i.e., revolutions per minute) with which the motors run must be in a certain range. Motors that run too slowly will not cool a computer properly; motors that run too fast will wear out prematurely. The following R chart monitors the amount of variability of the speed (in rpm's) of subgroups of 7 motors that have been selected each hour for testing: Does the rule give an "out Rule # of control" signal? (Check the box that applies) O Yes O No 1 9 2 R chart O Yes 11 O No 13 Subgroup number For a process such as this to be "in statistical control," only random patterns of points should appear on the control chart. The process is "not in statistical control" when any non-random patterns appear on the chart. Three commonly used tests or rules for signaling that a process may not be in statistical control are: • Rule 1: One or more points fall outside one of the chart's control limits • Rule 2: Nine points in a row are on the same side of the chart's centerline • Rule 3: Six points in a row are increasing (or decreasing). 15 17 Using these three rules, identify which (if any) of the rules gives an "out of control" signal, and indicate the subgroup number at which the signa is first given. What is the subgroup number at which the signal is first given? 0 0 □ 19 21 6

Each day, an electronics manufacturer creates thousands of small fan motors for computers. The speed (i.e., revolutions per minute) with which the motors run must be in a certain range. Motors that run too slowly will not cool a computer properly; motors that run too fast will wear out prematurely. The following R chart monitors the amount of variability of the speed (in rpm's) of subgroups of 7 motors that have been selected each hour for testing: Does the rule give an "out Rule # of control" signal? (Check the box that applies) O Yes O No 1 9 2 R chart O Yes 11 O No 13 Subgroup number For a process such as this to be "in statistical control," only random patterns of points should appear on the control chart. The process is "not in statistical control" when any non-random patterns appear on the chart. Three commonly used tests or rules for signaling that a process may not be in statistical control are: • Rule 1: One or more points fall outside one of the chart's control limits • Rule 2: Nine points in a row are on the same side of the chart's centerline • Rule 3: Six points in a row are increasing (or decreasing). 15 17 Using these three rules, identify which (if any) of the rules gives an "out of control" signal, and indicate the subgroup number at which the signa is first given. What is the subgroup number at which the signal is first given? 0 0 □ 19 21 6

MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
See similar textbooks
icon
Related questions
Question
= OTIME SERIES AND QUALITY CONTROL Interpreting a control chart Each day, an electronics manufacturer creates thousands of small fan motors for computers. The speed (i.e., revolutions per minute) with which the motors run must be in a certain range. Motors that run too slowly will not cool a computer properly; motors that run too fast will wear out prematurely. The following R chart monitors the amount of variability of the speed (in rpm's) of subgroups of 7 motors that have been selected each hour for testing: 1 1 3 Does the rule give an "out Rule # of control" signal? (Check the box that applies) O Yes O No 2 3 O Yes 7 Yes 9 R chart O No 11 • Rule 1: One or more points fall outside one of the chart's control limits O No • Rule 2: Nine points in a row are on the same side of the chart's centerline • Rule 3: Six points in a row are increasing (or decreasing). 13 Subgroup number For a process such as this to be "in statistical control," only random patterns of points should appear on the control chart. The process is "not in statistical control" when any non-random patterns appear on the chart. Three commonly used tests or rules for signaling that a process may not be in statistical control are: 15 Using these three rules, identify which (if any) of the rules gives an "out of control" signal, and indicate the subgroup number at which the signal is first given. What is the subgroup number at which the signal is first given? 17 0/3 19 X 21 S 6 0 -6 E E E
Transcribed Image Text:= OTIME SERIES AND QUALITY CONTROL Interpreting a control chart Each day, an electronics manufacturer creates thousands of small fan motors for computers. The speed (i.e., revolutions per minute) with which the motors run must be in a certain range. Motors that run too slowly will not cool a computer properly; motors that run too fast will wear out prematurely. The following R chart monitors the amount of variability of the speed (in rpm's) of subgroups of 7 motors that have been selected each hour for testing: 1 1 3 Does the rule give an "out Rule # of control" signal? (Check the box that applies) O Yes O No 2 3 O Yes 7 Yes 9 R chart O No 11 • Rule 1: One or more points fall outside one of the chart's control limits O No • Rule 2: Nine points in a row are on the same side of the chart's centerline • Rule 3: Six points in a row are increasing (or decreasing). 13 Subgroup number For a process such as this to be "in statistical control," only random patterns of points should appear on the control chart. The process is "not in statistical control" when any non-random patterns appear on the chart. Three commonly used tests or rules for signaling that a process may not be in statistical control are: 15 Using these three rules, identify which (if any) of the rules gives an "out of control" signal, and indicate the subgroup number at which the signal is first given. What is the subgroup number at which the signal is first given? 17 0/3 19 X 21 S 6 0 -6 E E E
TIME SERIES AND QUALITY CONTROL Interpreting a control chart QUYUTION A company that makes bolts and rivets used in assembling airplanes monitors the quality of its bolts by measuring the torque required to unloosen a bolt. When installed correctly, the bolts must be tight enough to withstand heavy vibration during flights but must be loose enough so that they can be removed periodically for maintenance. The following x-bar chart monitors the amount of torque required to loosen subgroups of 7 bolts that have been selected each hour for testing: x-bar chart Does the rule give an "out Rule of control signal? (Check the box that applies) Yes No No No For a process such as this to be "in statistical control," only random patterns of points should appear on the control chart. The process is "not in statistical control" when any non-random patterns appear on the chart. Three commonly used tests or rules for signaling that a process may not be in statistical control are: • Rule 1: One or more points fall outside one of the chart's control limits • Rule 2: Nine points in a row are on the same side of the chart's centerline • Rule 3: Six points in a row are increasing (or decreasing). 1 2 Using these three rules, identify which (if any) of the rules gives an "out of control" signal, and indicate the subgroup number at which the signal is first given. Yes Ⓒ Yes 11 Subgroup number 1 EXPLANATION The purpose of a control chart is to detect whether or not a process is "in statistical control," i.e., when the only factors influencing the process are small, unimportant random variations called chance causes by quality control practitioners. Any non-random behavior in a chart is taken to be an indication that some larger, more important factors are at work that should be investigated and, if possible, eliminated. Such factors are called assignable causes or special causes. Does the rule give an "out Rule of control signal? (Check the box that applies) Yes No Yes 2 There are many types of non-random patterns that one can look for in a control chart. The three rules given in this problem are among the most commonly used: 3 13 What is the subgroup number at which the signal is first given? 15 • Rule 1. Since the control limits are placed at a distance of three standard errors on either side of the chart's centerline, any points that fall outside the control limits have very low probabilities of occurrence and, therefore, are taken to be possible indications of process problems. • Rule 2. Random points should be equally likely to fall on either side of the chart's centerline. When too many successive points fall on the same side (either all above or all below) the chart's centerline, it is possible that some special cause is at work. More Practice 17 19 • Rule 3. Random points may show short movements in one direction or another, but not long trends. When too many successive points show an upward or a downward trend, then it is possible that a special cause may be the reason. In this problem, looking at the x-bar chart, we see that • Rule gives a signal and the signal is first given at subgroup 10. Rule 2 gives a signal and the signal is first given at subgroup 1. Rule 3 gives no signals of process problems. ANSWER Yes No No What is the subgroup number at which the signal is first given? 10 Evelyn V 1 U 9 8 6
Transcribed Image Text:TIME SERIES AND QUALITY CONTROL Interpreting a control chart QUYUTION A company that makes bolts and rivets used in assembling airplanes monitors the quality of its bolts by measuring the torque required to unloosen a bolt. When installed correctly, the bolts must be tight enough to withstand heavy vibration during flights but must be loose enough so that they can be removed periodically for maintenance. The following x-bar chart monitors the amount of torque required to loosen subgroups of 7 bolts that have been selected each hour for testing: x-bar chart Does the rule give an "out Rule of control signal? (Check the box that applies) Yes No No No For a process such as this to be "in statistical control," only random patterns of points should appear on the control chart. The process is "not in statistical control" when any non-random patterns appear on the chart. Three commonly used tests or rules for signaling that a process may not be in statistical control are: • Rule 1: One or more points fall outside one of the chart's control limits • Rule 2: Nine points in a row are on the same side of the chart's centerline • Rule 3: Six points in a row are increasing (or decreasing). 1 2 Using these three rules, identify which (if any) of the rules gives an "out of control" signal, and indicate the subgroup number at which the signal is first given. Yes Ⓒ Yes 11 Subgroup number 1 EXPLANATION The purpose of a control chart is to detect whether or not a process is "in statistical control," i.e., when the only factors influencing the process are small, unimportant random variations called chance causes by quality control practitioners. Any non-random behavior in a chart is taken to be an indication that some larger, more important factors are at work that should be investigated and, if possible, eliminated. Such factors are called assignable causes or special causes. Does the rule give an "out Rule of control signal? (Check the box that applies) Yes No Yes 2 There are many types of non-random patterns that one can look for in a control chart. The three rules given in this problem are among the most commonly used: 3 13 What is the subgroup number at which the signal is first given? 15 • Rule 1. Since the control limits are placed at a distance of three standard errors on either side of the chart's centerline, any points that fall outside the control limits have very low probabilities of occurrence and, therefore, are taken to be possible indications of process problems. • Rule 2. Random points should be equally likely to fall on either side of the chart's centerline. When too many successive points fall on the same side (either all above or all below) the chart's centerline, it is possible that some special cause is at work. More Practice 17 19 • Rule 3. Random points may show short movements in one direction or another, but not long trends. When too many successive points show an upward or a downward trend, then it is possible that a special cause may be the reason. In this problem, looking at the x-bar chart, we see that • Rule gives a signal and the signal is first given at subgroup 10. Rule 2 gives a signal and the signal is first given at subgroup 1. Rule 3 gives no signals of process problems. ANSWER Yes No No What is the subgroup number at which the signal is first given? 10 Evelyn V 1 U 9 8 6
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman
SEE MORE TEXTBOOKS