Question 1

What is the definition of rational subgroups?

Accepted Answer

A) They are those parts of a process that are identified as most likely to be special causes. 
B) They are samples chosen to reflect only item-to-item variation in a process. 
C) They are those samples in an s chart that are in control. 
D) They are the specific groups of charts that we use to monitor a process. 
A) They are those parts of a process that are identified as most likely to be special causes. 
B) They are samples chosen to reflect only item-to-item variation in a process. 
C) They are those samples in an s chart that are in control. 
D) They are the specific groups of charts that we use to monitor a process.

Question 2

An important characteristic in the proper operation of ignition keys for automobiles is the groove width of the key.In a large manufacturing plant that produces thousands of keys,control charts have been established to monitor the process of cutting the groove.It is believed that the measurement (in inches)of the groove width is Normally distributed.Over a period of time,20 samples,each of size n = 5,were selected in order to establish 3-sigma   and s charts.From these samples the following were determined:     = 0.15932 and    
= 0.0193438.Examination of the   chart and the s chart for the samples led to the conclusion that the process was in control at this time.What,then,are the estimates of the process mean,F1F1F1S1F1F1F10,and process standard deviation,F1F1F1S1F1F1F10?

Accepted Answer

A)  
   
= 0.00797;
   
= 0.000967 
B)  
   
= 0.00797;
   
= 0.019344 
C)  
   
= 0.15932;
   
= 0.020578 
D)  
   
= 0.15932;
   
= 0.001029 
E)  
   
= 0.00797;
   
= 0.001029 
A)  
   
= 0.00797;
   
= 0.000967 
B)  
   
= 0.00797;
   
= 0.019344 
C)  
   
= 0.15932;
   
= 0.020578 
D)  
   
= 0.15932;
   
= 0.001029 
E)  
   
= 0.00797;
   
= 0.001029

Question 3

It is said that "the first step to improving a process is to understand it." Which of the following may be helpful in gaining an understanding of the process?

Accepted Answer

A) A flowchart showing all the stages of a process 
B) A cause-and-effect diagram showing the logical relationships between the inputs,the stages of a process,and the outputs 
C) A histogram of the measurements made at a specific stage of the process 
D) Any and all of the above 
E) Only A and B 
A) A flowchart showing all the stages of a process 
B) A cause-and-effect diagram showing the logical relationships between the inputs,the stages of a process,and the outputs 
C) A histogram of the measurements made at a specific stage of the process 
D) Any and all of the above 
E) Only A and B

Question 4

Parts manufactured by an injection molding process are subjected to a compressive strength test.We monitor the compressive strength of the parts manufactured by this process using an   and an s control chart.Samples of size 9 are taken at regular intervals,and their mean compressive strength (in psi = pounds per square inch)and standard deviation are plotted on the charts in time order.The overall mean of the sample means is     = 81.2 psi,and the mean of the sample standard deviations is   = 2.9 psi.The control chart constants are (partially)reproduced below.   What is the value of the center line for the   chart?

Accepted Answer

A) 18.8 psi 
B) 78.7 psi 
C) 81.2 psi 
D) 138.6 psi 
A) 18.8 psi 
B) 78.7 psi 
C) 81.2 psi 
D) 138.6 psi

Question 5

Parts manufactured by an injection molding process are subjected to a compressive strength test.We monitor the compressive strength of the parts manufactured by this process using an   and an s control chart.Samples of size 9 are taken at regular intervals,and their mean compressive strength (in psi = pounds per square inch)and standard deviation are plotted on the charts in time order.The overall mean of the sample means is     = 81.2 psi,and the mean of the sample standard deviations is   = 2.9 psi.The control chart constants are (partially)reproduced below.   What is the center line for the s chart?

Accepted Answer

A) 2.8 psi 
B) 2.9 psi 
C) 3 psi 
D) 5.0 psi 
A) 2.8 psi 
B) 2.9 psi 
C) 3 psi 
D) 5.0 psi

Question 6

What is the name of a chart in which the standard deviations of samples taken at regular intervals are plotted against the time order in which the samples were taken?

Accepted Answer

A) An s chart 
B) An    
Chart 
C) An R chart 
D) A p chart 
A) An s chart 
B) An    
Chart 
C) An R chart 
D) A p chart

Question 7

A random sample of items was selected from all items produced in a day of production.Each item was examined to determine if the item conformed to the customer's specifications.This was repeated over 20 days with a sample of 150 items chosen each day.At the end of the 20 days,it was determined that a total of 69 items failed and were declared to be nonconforming.The following chart,which shows the proportion of nonconforming items for each day,was produced.   From the chart,what can be said about the process at this point?

Accepted Answer

The process is not i

Question 8

Which of the following is an example of a process?

Accepted Answer

A) Reading through all your email every day and determining whether or not to reply 
B) Reading all your friends' Facebook status updates and deciding whether or not to add a comment 
C) Going through your music library to determine which songs you will put on your smart phone 
D) All of the above 
A) Reading through all your email every day and determining whether or not to reply 
B) Reading all your friends' Facebook status updates and deciding whether or not to add a comment 
C) Going through your music library to determine which songs you will put on your smart phone 
D) All of the above

Question 9

A variable is measured periodically on a process.Suppose the variable continues to be described by the same distribution when observed over time.What can we say about this variable?

Accepted Answer

A) It is nonrandom. 
B) It is in statistical control. 
C) It is a simple random variable. 
D) It is natural. 
A) It is nonrandom. 
B) It is in statistical control. 
C) It is a simple random variable. 
D) It is natural.

Question 10

You have been invited to give a special address at the Joint Statistics Meeting on your research area.You are allotted 1 hour to give your talk.You practice your talk many times in order to make sure it is perfect and within the time constraints.What is a special cause variation for the length of the talk?

Accepted Answer

A) The variation in the length of the talk caused by you intentionally speaking quickly in a few of your practice sessions so that you can finish the talk quickly in order to attend an impromptu meeting 
B) The variation in the length of the talk caused by variation in the speed with which you talk and the amount of words used during each practice session 
C) All of the above 
D) None of the above 
A) The variation in the length of the talk caused by you intentionally speaking quickly in a few of your practice sessions so that you can finish the talk quickly in order to attend an impromptu meeting 
B) The variation in the length of the talk caused by variation in the speed with which you talk and the amount of words used during each practice session 
C) All of the above 
D) None of the above

Question 11

Why is statistical control necessary?

Accepted Answer

A) If a process is in control,then we know exactly what the final output will be at the end. 
B) If a process is in control,then we have a good idea of what to expect in the end. 
C) Actually,statistical control is not necessary or desirable. 
A) If a process is in control,then we know exactly what the final output will be at the end. 
B) If a process is in control,then we have a good idea of what to expect in the end. 
C) Actually,statistical control is not necessary or desirable.

Question 12

Cpk should be based on at least how many measurements?

Accepted Answer

A) 1 
B) 10 
C) 50 
D) 100 
A) 1 
B) 10 
C) 50 
D) 100

Question 13

Which of the following is an example of special cause variation?

Accepted Answer

A) Every day you spend 1 hour cooking dinner for your kids,and they always love the meal.However,today you came home and the electricity was out,so all of the food is spoiled.Hence,you order takeout. 
B) Every day you spend 1 hour cooking dinner for your kids,and they always love the meal.However,today you are late getting home from work so you cook dinner 1 hour later than usual. 
C) Every day you spend 1 hour cooking dinner for your kids,but your kids usually do not like what you cook. 
D) None of the above 
A) Every day you spend 1 hour cooking dinner for your kids,and they always love the meal.However,today you came home and the electricity was out,so all of the food is spoiled.Hence,you order takeout. 
B) Every day you spend 1 hour cooking dinner for your kids,and they always love the meal.However,today you are late getting home from work so you cook dinner 1 hour later than usual. 
C) Every day you spend 1 hour cooking dinner for your kids,but your kids usually do not like what you cook. 
D) None of the above

Question 14

Piston rings for an automotive engine are produced by a forging process.We wish to monitor the inside diameter of the rings manufactured by this process using an     and an s control chart.Samples of size 4 are to be taken at regular intervals,and the sample means and standard deviations are computed and plotted on the charts in time order.The target values for the inside diameter are a mean of F1F1F1S1F1F1F10 = 75 millimeters and a standard deviation of F1F1F1S1F1F1F10 = 0.02 millimeters.The control chart constants are (partially)reproduced below.   What is the center line for the s chart?

Accepted Answer

A) 0.018 millimeters 
B) 0.02 millimeters 
C) 0.04 millimeters 
D) 75 millimeters 
A) 0.018 millimeters 
B) 0.02 millimeters 
C) 0.04 millimeters 
D) 75 millimeters

Question 15

What condition is necessary for a process to be capable?

Accepted Answer

A) The process must be in control. 
B) The process must meet external specifications. 
C) The process must not have any runs. 
D) None of the above 
A) The process must be in control. 
B) The process must meet external specifications. 
C) The process must not have any runs. 
D) None of the above

Question 16

Piston rings for an automotive engine are produced by a forging process.We monitor the inside diameter of the rings manufactured by this process using an     and an s control chart.Samples of size 4 are taken at regular intervals,and the sample means and standard deviations are computed and plotted on the charts in time order.The overall mean of the sample means is    
= 73.97 millimeters,and the sample standard deviation of all measurements is s = 0.03 millimeters.Specifications call for the inside diameter of the rings to be 74.00 ± 0.10 millimeters.The control chart constants are (partially)reproduced below.   What is the value of an estimate of the capability index Cp?

Accepted Answer

A) 0.72 
B) 0.78 
C) 1.02 
D) 1.11 
A) 0.72 
B) 0.78 
C) 1.02 
D) 1.11

Question 17

Parts manufactured by an injection molding process are subjected to a compressive strength test.We wish to monitor the compressive strength of the parts manufactured by this process using both     and s charts.Samples of size 9 are to be taken at regular intervals,and their mean compressive strength (in psi = pounds per square inch)and standard deviation are plotted on the charts in time order.The target values for the compressive strengths are a mean of F1F1F1S1F1F1F10 = 80 psi and a standard deviation of F1F1F1S1F1F1F10 = 3 psi.The control chart constants are (partially)reproduced below.   What is the upper control limit for the s chart?

Accepted Answer

A) 0.7 psi 
B) 2.9 psi 
C) 5.1 psi 
D) 12 psi 
A) 0.7 psi 
B) 2.9 psi 
C) 5.1 psi 
D) 12 psi

Question 18

Which of the following is an example of a process that is in control but does not have capability?

Accepted Answer

A) A university builds new dormitories that most students give a high ranking of 5.7 out of 6 for the best place to live in the Washington,DC,area.However,very few students actually choose to live in the new dormitories when school starts. 
B) A university builds new dormitories that students give a low ranking of 1.4 out of 6 for the best place to live in the Washington,DC,area.Therefore,very few students actually choose to live in the new dormitories. 
C) A university builds new dormitories that are plagued with problems.Average rankings from students of the new dormitories range from 1 to 6 out of a possible 7. 
D) None of the above 
A) A university builds new dormitories that most students give a high ranking of 5.7 out of 6 for the best place to live in the Washington,DC,area.However,very few students actually choose to live in the new dormitories when school starts. 
B) A university builds new dormitories that students give a low ranking of 1.4 out of 6 for the best place to live in the Washington,DC,area.Therefore,very few students actually choose to live in the new dormitories. 
C) A university builds new dormitories that are plagued with problems.Average rankings from students of the new dormitories range from 1 to 6 out of a possible 7. 
D) None of the above

Question 19

At the start of the semester,a professor wants to monitor students who miss class.The professor implements a new attendance policy geared toward encouraging students to attend class every day.There are currently 150 registered students in the class,and each day the class takes a quiz that is just used to measure attendance.The number of quizzes that are turned in will serve as the measure of attendance.The quizzes are given at every class period and the class meets four times per week over a 15-week semester.Would creating a single p chart be useful for this situation with all students and the number of days missed on the same chart?

Accepted Answer

A) Yes,the number of students registered in the course will remain the same from day to day and the students are taking the course from the same professor. 
B) No,it may be better to divide students up by the TA who is assigned to assist with the grading of the quizzes and make separate control charts for each TA's group of students. 
C) No,separate charts should be made for the male and female students. 
D) None of the above are appropriate reasons. 
A) Yes,the number of students registered in the course will remain the same from day to day and the students are taking the course from the same professor. 
B) No,it may be better to divide students up by the TA who is assigned to assist with the grading of the quizzes and make separate control charts for each TA's group of students. 
C) No,separate charts should be made for the male and female students. 
D) None of the above are appropriate reasons.

Question 20

Piston rings for an automotive engine are produced by a forging process.We monitor the inside diameter of the rings manufactured by this process using an   and an s control chart.Samples of size 4 are taken at regular intervals,and the sample means and standard deviations are computed and plotted on the charts in time order.The overall mean of the sample means is 73.812 millimeters,and the mean of the sample standard deviations is 0.022 millimeters.The control chart constants are (partially)reproduced below.   What is the lower control limit for the s chart?

Accepted Answer

A) -0.066 millimeters 
B) 0 millimeters 
C) 0.020 millimeters 
D) 0.022 millimeters 
A) -0.066 millimeters 
B) 0 millimeters 
C) 0.020 millimeters 
D) 0.022 millimeters

What is the definition of rational subgroups?

It is said that "the first step to improving a process is to understand it." Which of the following may be helpful in gaining an understanding of the process?

What is the name of a chart in which the standard deviations of samples taken at regular intervals are plotted against the time order in which the samples were taken?

Which of the following is an example of a process?

A variable is measured periodically on a process.Suppose the variable continues to be described by the same distribution when observed over time.What can we say about this variable?

Why is statistical control necessary?

C_pk should be based on at least how many measurements?

Which of the following is an example of special cause variation?

What condition is necessary for a process to be capable?

Which of the following is an example of a process that is in control but does not have capability?

Looking at Datadistributions

Looking at Datarelationships

Producing Data

Probability: the Study of Randomness

Sampling Distributions

Introduction to Inference

Inference for Means

Inference for Proportions

Inference for Categorical Data

Inference for Regression

Multiple Regression

One-Way Analysis of Variance

Two-Way Analysis of Variance

Logistic Regression

Nonparametric Tests

Bootstrap Methods and Permutation Tests

Filters

Exam 17: Statistics for Quality: Control and Capability

What is the definition of rational subgroups?

It is said that "the first step to improving a process is to understand it." Which of the following may be helpful in gaining an understanding of the process?

What is the name of a chart in which the standard deviations of samples taken at regular intervals are plotted against the time order in which the samples were taken?

Which of the following is an example of a process?

A variable is measured periodically on a process.Suppose the variable continues to be described by the same distribution when observed over time.What can we say about this variable?

Why is statistical control necessary?

Cpk should be based on at least how many measurements?

Which of the following is an example of special cause variation?

What condition is necessary for a process to be capable?

Which of the following is an example of a process that is in control but does not have capability?

Looking at Datadistributions

Looking at Datarelationships

Producing Data

Probability: the Study of Randomness

Sampling Distributions

Introduction to Inference

Inference for Means

Inference for Proportions

Inference for Categorical Data

Inference for Regression

Multiple Regression

One-Way Analysis of Variance

Two-Way Analysis of Variance

Logistic Regression

Nonparametric Tests

Bootstrap Methods and Permutation Tests

Filters

C_pk should be based on at least how many measurements?