Question 1

A p chart is a control chart on which the proportions of nonconforming units are plotted versus time.

Accepted Answer

A) True 
 B)False  True

Question 2

A powder metal manufacturing company is producing sleeves for a locking mechanism.The target (nominal)value for the inside diameter is 1 inch.The inside diameter specifications are 1 ± .005 inches.Assume that the process is in statistical control with $\overline { \overline { X } }$

= 1)0002 inches, $\overline { \mathrm { R } }$
= )003 inches,and subgroup size of 5.Calculate the estimated proportion of out-of-specification sleeve inside diameters.

Accepted Answer

A) .0471 
B) .0217 
C) .0001 
D) .4783 
E) .0139 
A) .0471 
B) .0217 
C) .0001 
D) .4783 
E) .0139 C

Question 3

If $\overline { \overline { X } }$

= 2)0144, $\bar { R }$
= )0972,and there are 25 subgroups of size 5,find the UCL and the LCL for the $\bar { x }$
Chart.

Accepted Answer

A) [1.999,2.029] 
B) [1.958,2.071] 
C) [1.917,2.112] 
D) [1.437,2.591] 
A) [1.999,2.029] 
B) [1.958,2.071] 
C) [1.917,2.112] 
D) [1.437,2.591] B

Question 4

If the process variability steadily increases,we would observe:

Accepted Answer

A) An alternating pattern of a high value followed by a low value on the R chart. 
B) An upward trend on the R chart. 
C) A downward trend on the R chart. 
D) A increasing gradual funnel pattern on the R chart. 
E) A decreasing gradual funnel pattern on the R chart. 
A) An alternating pattern of a high value followed by a low value on the R chart. 
B) An upward trend on the R chart. 
C) A downward trend on the R chart. 
D) A increasing gradual funnel pattern on the R chart. 
E) A decreasing gradual funnel pattern on the R chart.

Question 5

A manufacturer of windows produces one type that has a plastic coating.The specification limits for the plastic coating are 30 and 70.From time to time the plastic coating can become uneven.Therefore,to keep the coating as even as possible,thickness measurements are periodically taken at four different locations on the window.15 subgroups were observed,each consisting of four thickness measurements,with the following results: mean of the means = $\overline { \overline{ x } }$

= 50.05,and average range of 8.85.Is the process capable of meeting the specifications?

Accepted Answer

A) Yes 
B) No 
A) Yes 
B) No

Question 6

A motorcycle manufacturer produces the parts for its vehicles in different locations and transports them to its plant for assembly.In order to keep the assembly operations running efficiently,it is vital that all parts be within specification limits.One important part used in the assembly is the engine camshaft,and one important quality characteristic is the case hardness depth.Specifications state that the hardness depth must be between 3.0 mm and 6.0 mm.To investigate the process,the quality control engineer selected 25 daily subgroups of n = 5 and measured the hardness depth.The process yielded a mean of the means $\overline { \overline{ x } }$

= 4)50 and an average range = 1.01.Calculate the center line for the R chart.

Accepted Answer

A) 1.01 
B) 0.22 
C) 4.50 
D) 0.90 
A) 1.01 
B) 0.22 
C) 4.50 
D) 0.90

Question 7

Unusual sources of variation that can be attributed to specific causes are called the common causes of process variation.

Accepted Answer

A) True 
 B)False

Question 8

A control chart is a graph whose purpose is to detect assignable causes of variation in a process.

Accepted Answer

A) True 
 B)False

Question 9

For a given control chart,zone boundaries consist of the UCL and LCL.

Accepted Answer

A) True 
 B)False

Question 10

In a manufacturing process,if the limits for a control chart are set too _____________,the risk of not investigating a special cause of variation and possibly not taking a corrective action ____________.

Accepted Answer

A) Tight,increases 
B) Loose,increases 
C) Loose,decreases 
D) None of these 
A) Tight,increases 
B) Loose,increases 
C) Loose,decreases 
D) None of these

Question 11

Process leeway is the distance between natural tolerance limits and control limits.

Accepted Answer

A) True 
 B)False

Question 12

Suppose that $\overline { \mathrm { X } }$
And R charts based on subgroups of size 4 are being used to monitor the tire diameter of a new radial tire.The $\overline { \mathrm { X } }$
And R charts are found to be in statistical control,with $\overline { \overline { X } } = 50.5 , \bar { R } = 1.25$

Inches.A histogram of the tire diameter measurements indicates that these measurements are approximately normally distributed.Compute the natural tolerance limits for this process.

Accepted Answer

A) [48.68,52.32] 
B) [49.89,51.11] 
C) [48.86,52.14] 
D) [46.75,54.25] 
A) [48.68,52.32] 
B) [49.89,51.11] 
C) [48.86,52.14] 
D) [46.75,54.25]

Question 13

If 20 samples of size 7 are drawn,with $\overline { \overline { X } }$

= 33.33 and $\bar { R }$
= 5)65,what are the LCL and the UCL for the $\bar { X }$
Chart?

Accepted Answer

A) [32.313,34.347] 
B) [30.963,35.697] 
C) [27.68,38,98] 
D) [32.911,33.749] 
A) [32.313,34.347] 
B) [30.963,35.697] 
C) [27.68,38,98] 
D) [32.911,33.749]

Question 14

Rational subgrouping allows us to detect changes ____________ subgroups.

Accepted Answer

A) Within 
B) Between 
C) In the sizes of 
D) None of these 
A) Within 
B) Between 
C) In the sizes of 
D) None of these

Question 15

A foreman wants to use an $\overline { \mathrm { X } }$
Chart to control the average length of the bolts manufactured.He has recently collected the six samples given below. $$\begin{array} { c c c c c } 
\text { Sample } & & & & \
1 & 1.99 & 2.01 & 2.02 & 2.02 \
2 & 2.00 & 2.00 & 2.01 & 2.01 \
3 & 1.98 & 1.99 & 2.01 & 1.98 \
4 & 2.01 & 2.02 & 2.02 & 1.99 \
5 & 1.99 & 1.99 & 2.01 & 1.99 \
6 & 2.03 & 1.98 & 2.03 & 2.04
\end{array}$$
Calculate the average range.

Accepted Answer

A) .036 
B) .18 
C) .030 
D) .05 
A) .036 
B) .18 
C) .030 
D) .05

Question 16

If $\overline { \overline { X } }$

= 5)2, $\bar { R }$
= )3,and n = 4,calculate the natural tolerance limits.

Accepted Answer

A) [5.054,5.346] 
B) [4.3,6.1] 
C) [4.806,5.594] 
D) [4.763,5.637] 
A) [5.054,5.346] 
B) [4.3,6.1] 
C) [4.806,5.594] 
D) [4.763,5.637]

Question 17

Common causes of variation represent the inherent variability of a given process.

Accepted Answer

A) True 
 B)False

Question 18

A fastener company produces bolts with a nominal (target)length of 2.00 inches.The specifications are 2.00 ± .006 inches.If the process mean is 2.001 and the process standard deviation is .0016,determine the estimated standard deviations of the leeway for this process.

Accepted Answer

A) .0016 
B) .0048 
C) 1.375 
D) .125 
A) .0016 
B) .0048 
C) 1.375 
D) .125

Question 19

A powder metal manufacturing company is producing sleeves for a locking mechanism.The target (nominal)value for the inside diameter is 1 inch.The inside diameter specifications are 1 ± .005 inches.Assume that the process is in statistical control with $\overline { \overline { X } }$

= 1)0002 inches, $\overline { \mathrm { R } }$
= )003 inches,and subgroup size of 5.What is the sigma level capability for this process?

Accepted Answer

A) 3.0 
B) 3.72 
C) 1.6 
D) 1.0 
E) 2.72 
A) 3.0 
B) 3.72 
C) 1.6 
D) 1.0 
E) 2.72

Question 20

Sigma level capability is the number of estimated process standard deviations between the estimated process mean and the specification limit closest to the estimated process mean.

Accepted Answer

A) True 
 B)False

A p chart is a control chart on which the proportions of nonconforming units are plotted versus time.

If $\overline { \overline { X } }$ = 2)0144, $\bar { R }$ = )0972,and there are 25 subgroups of size 5,find the UCL and the LCL for the $\bar { x }$ Chart.

If the process variability steadily increases,we would observe:

Unusual sources of variation that can be attributed to specific causes are called the common causes of process variation.

A control chart is a graph whose purpose is to detect assignable causes of variation in a process.

For a given control chart,zone boundaries consist of the UCL and LCL.

In a manufacturing process,if the limits for a control chart are set too _,the risk of not investigating a special cause of variation and possibly not taking a corrective action .

Process leeway is the distance between natural tolerance limits and control limits.

If 20 samples of size 7 are drawn,with $\overline { \overline { X } }$ = 33.33 and $\bar { R }$ = 5)65,what are the LCL and the UCL for the $\bar { X }$ Chart?

Rational subgrouping allows us to detect changes ____________ subgroups.

If $\overline { \overline { X } }$ = 5)2, $\bar { R }$ = )3,and n = 4,calculate the natural tolerance limits.

Common causes of variation represent the inherent variability of a given process.

A fastener company produces bolts with a nominal (target)length of 2.00 inches.The specifications are 2.00 ± .006 inches.If the process mean is 2.001 and the process standard deviation is .0016,determine the estimated standard deviations of the leeway for this process.

Sigma level capability is the number of estimated process standard deviations between the estimated process mean and the specification limit closest to the estimated process mean.

Statistical Inferences for Population Variances

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression and Model Building

Time Series Forecasting and Index Numbers

Nonparametric Methods

Decision Theory

Filters

Exam 17: Process Improvement Using Control Charts

A p chart is a control chart on which the proportions of nonconforming units are plotted versus time.

If X‾‾\overline { \overline { X } }X = 2)0144, Rˉ\bar { R }Rˉ = )0972,and there are 25 subgroups of size 5,find the UCL and the LCL for the xˉ\bar { x }xˉ Chart.

If the process variability steadily increases,we would observe:

Unusual sources of variation that can be attributed to specific causes are called the common causes of process variation.

A control chart is a graph whose purpose is to detect assignable causes of variation in a process.

For a given control chart,zone boundaries consist of the UCL and LCL.

In a manufacturing process,if the limits for a control chart are set too _____________,the risk of not investigating a special cause of variation and possibly not taking a corrective action ____________.

Process leeway is the distance between natural tolerance limits and control limits.

If 20 samples of size 7 are drawn,with X‾‾\overline { \overline { X } }X = 33.33 and Rˉ\bar { R }Rˉ = 5)65,what are the LCL and the UCL for the Xˉ\bar { X }Xˉ Chart?

Rational subgrouping allows us to detect changes ____________ subgroups.

If X‾‾\overline { \overline { X } }X = 5)2, Rˉ\bar { R }Rˉ = )3,and n = 4,calculate the natural tolerance limits.

Common causes of variation represent the inherent variability of a given process.

A fastener company produces bolts with a nominal (target)length of 2.00 inches.The specifications are 2.00 ± .006 inches.If the process mean is 2.001 and the process standard deviation is .0016,determine the estimated standard deviations of the leeway for this process.

Sigma level capability is the number of estimated process standard deviations between the estimated process mean and the specification limit closest to the estimated process mean.

Statistical Inferences for Population Variances

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression and Model Building

Time Series Forecasting and Index Numbers

Nonparametric Methods

Decision Theory

Filters

If $\overline { \overline { X } }$ = 2)0144, $\bar { R }$ = )0972,and there are 25 subgroups of size 5,find the UCL and the LCL for the $\bar { x }$ Chart.

In a manufacturing process,if the limits for a control chart are set too _,the risk of not investigating a special cause of variation and possibly not taking a corrective action .

If 20 samples of size 7 are drawn,with $\overline { \overline { X } }$ = 33.33 and $\bar { R }$ = 5)65,what are the LCL and the UCL for the $\bar { X }$ Chart?

If $\overline { \overline { X } }$ = 5)2, $\bar { R }$ = )3,and n = 4,calculate the natural tolerance limits.