CQIA Statistical Methods 2

Question 1

A process has a mean of 50 and a standard deviation of 5. What percentage of data falls within one standard deviation of the mean (45 to 55) in a normal distribution?

Accepted Answer

68%

Answer

In a normal distribution, approximately 68% of data falls within ±1 standard deviation of the mean.

Question 2

Which type of data can be ranked but does not have equal intervals between values?

Accepted Answer

Ordinal data

Answer

Ordinal data can be ranked in order, but the differences between ranks are not necessarily equal.

Question 3

A run chart shows 8 consecutive data points above the centerline. This is an indicator of:

Accepted Answer

A special cause

Answer

Eight or more consecutive points on one side of the centerline signal a non-random pattern indicating a special cause.

Question 4

What does a p-chart monitor in statistical process control?

Accepted Answer

Proportion of defective units

Answer

A p-chart tracks the proportion (fraction) of nonconforming (defective) units in a sample.

Question 5

Which measure of central tendency is most affected by extreme outliers?

Accepted Answer

Mean

Answer

The mean is calculated using all values, so extreme outliers pull it significantly toward them.

(CQIA) ASQ Certified Quality Improvement Associate Practice Test

(CQIA) ASQ Certified Quality Improvement Associate Practice Test

CQIA Statistical Methods 2