Statistical Quality Control Practice Test 4

1. MR (Moving Range) is defined as

The difference between the highest observation and mean of observations

The difference between any two successive observations

The difference of highest observation and the lowest observation

The difference between the lowest observation and mean of the observations

2. If the sample size for a p-chart is 50 and the value for the center line of the chart is 0.2313, what will be the value of the LCL of the chart?

0.0524

0.4108

0.0762

0.0389

3. “\(\widehat{σ_3} = 1.047\overline{MR}\); where \(\overline{MR}\) is the median of the span-two moving ranges.”

False

True

4. When there is no standard given, the value of LCL for the c-chart is given by ___________

LCL=\(\bar{c}+2\sqrt{\bar{c}}\)

LCL=\(\bar{c}-3\sqrt{\bar{c}}\)

LCL=\(\bar{c}+3\sqrt{\bar{c}}\)

LCL=\(\bar{c}-2\sqrt{\bar{c}}\)

5. For mean of all sample standard deviations=0.0094 and the sample size= 5, what will be the estimate of process standard deviation?

100

0.01

0.0094

6. If there are 9 items defective in the sample size of 28, what will be the value that the fraction nonconforming chart, will represent?

0.3214

0.2971

0.8172

0.6328

7. If type II error probability for a process is 0.8594, its ARL will be ____

8. What is done when there is a sample plotted out of control limits for a p-chart?

All the samples are investigated

The sample is only investigated for an assignable cause

The sample is not investigated at all (It is assumed that there was no assignable cause present)

The sample is investigated for an assignable cause and then the sample data is eliminated to develop a new p-chart

9. The gap between the UCL and LCL is double the gap between either one of them and the Center line, for the standardized chart.

True

False

10. The control charts based directly on the sample variance are called ____________

s Control charts

σ² Control charts

s² Control charts

x Charts