If all sample averages on an -chart fall within

QUESTION 1

1. If all sample averages on an -chart fall within the control limits, all output will be conforming.

   True

   False

4 points

QUESTION 2

1. Process control and process capability are synonymous terms.

   True

   False

4 points

QUESTION 3

1. When monitoring attribute data using a p-chart, if the subgroup size is not constant, variable control limits can be established.

   True

   False

4 points

QUESTION 4

1. If the mean contaminant count per squared millimeter is 5.8, then the center line for a c-chart that plots the contaminant count per squared centimeter is 580.

   True

   False

4 points

QUESTION 5

1. When constructing control limits, if special causes are found, they are eliminated and the control limits recomputed because the special cause points do not represent a state of statistical control.

   True

   False

4 points

QUESTION 6

1. The s-chart is used to monitor variation.

   True

   False

4 points

QUESTION 7

1. An s-chart utilizes the range instead of the standard deviation utilized in R-charts.

   True

   False

4 points

QUESTION 8

1. Control charts for individual variables data require calculation of a moving range.

   True

   False

4 points

QUESTION 9

1. Subgroup samples should be chosen so that, if assignable causes are present, the chance of observing differences between samples is low, while the chance of observing differences within a sample is high.

   True

   False

4 points

QUESTION 10

1. For variables data, sample size can be calculated by specifying the desired minimum shift in the process mean to be detected.

   True

   False

4 points

QUESTION 11

1. A process is deemed “out of control” when

   common causes are present.

   special causes are present.

   data varies around the mean.

   defective rate is high.

4 points

QUESTION 12

1. _____________ developed the first control charts.

   G. Taguchi

   Walter Shewhart

   W. Edwards Deming

   Dr. Joseph Moses Juran

4 points

QUESTION 13

1. A manufacturing company producing circuit boards will randomly sample 60 circuit boards per day and record the number of defects contained in each of these boards. Management wants to plot the number of defects in all the circuit boards sampled. What control chart is most appropriate?

   -chart

   p-chart

   np-chart

   c-chart

4 points

QUESTION 14

1. A delivery company defines a “defective” as a package delivered later than the promised delivery time. Management wants to monitor the proportion of packages delivered per week beyond the promised delivery time. Management is willing to sample 150 packages per week and determine which of these packages are “defective.” What control chart is most appropriate?

   -chart

   R-chart

   p-chart

   c-chart

4 points

QUESTION 15

1. Determine the sample standard deviation for the following sample data: 7, 9, 2, 0, 1 and 5.

   3.3466

   3.2660

   2.9933

   3.5777

4 points

QUESTION 16

1. Suppose that a substrate is built from layers so that its thickness is the sum of the thicknesses of each layer. The thickness of each layer has the following means and standard deviations. What is the probability that the substrate thickness exceeds 110 units?
   
   Layer, Mean, Standard deviation
   1, 20, 4
   2, 30, 8
   3, 50, 10

   0.325

   0.227

   0.478

   0.536

4 points

QUESTION 17

1. In the application of an xbar control chart with the usual 3-sigma limits, if the subgroup sample size is increased

   the Type I errors decrease, and the Type II errors increase.

   the Type I errors remain the same and the Type II errors increase.

   the Type I errors remain the same and the Type II errors decrease.

   both the Type I and Type II errors decrease.

4 points

QUESTION 18

1. For an xbar and R control chart use the following summary statistics: = 10.0, =2.3, and n=4 to answer the following questions.
   (Note: Use the above scenario and data to answer questions 18-20.)
   
   Calculate an unbiased estimate of .

   2.4965

   1.117

   2.039

   2.883

4 points

QUESTION 19

1. (Use scenario from question 18 above.)
   
   Calculate the upper control limit for an xbar control chart.

   16.9

   13.35

   14.234

   11.677

4 points

QUESTION 20

1. (Use scenario from question 18 above.)
   
   Calculate the upper control limit for an R control chart.

   5.249

   9.146

   14.234

   9.26

4 points

QUESTION 21

1. For an xbar and s control charts given the following summary statistics: =10.0, =2.3, and n = 4. Calculate an unbiased estimate of .

   2.039

   1.117

   2.497

   2.883

4 points

QUESTION 22

1. Assume gage = 2.497. The upper specification limit USL=16 and lower specification limit LSL=4. Using k=6, what is the precision-to-tolerance (P/T) ratio?

   1.0195

   0.585

   1.2485

   1.4415

4 points

QUESTION 23

1. Twenty-five samples, of size 30 were collected and a total of 48 nonconforming items were found. The three sigma upper control limit for a p-chart is

   0.198

   0.091

   0.211

   0.833

4 points

QUESTION 24

1. Given that process=4.7 and gage=3.4. What is the total standard deviation in data from this process?

   3.245

   8.1

   5.801

   33.65

4 points

QUESTION 25

1. Given an 3-sigma xbar chart for n=4 with UCL=16 and LCL=4, the estimated process standard deviation is

   4

   2

   16

   8