A Study Over a 10-Year Period Showed That a Certain

question 97

Multiple Choice

A study over a 10-year period showed that a certain mammogram test had a 50 percent rate of false positives.This indicates that

• A)about half the tests indicated cancer.
• B)about half the tests missed a cancer that exists.
• C)about half the tests showed a cancer that did not exist.
• D)about half the women tested actually had no cancer.

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Definitions:

Z-test

A Z-test is a statistical test used to determine whether two population means are different when the variances are known and the sample size is large.

Sample Mean

The sample mean is the average value of a sample set of numbers, calculated as the sum of the individual values divided by the number of values in the sample.

Population Mean

The average of all the items in a population, representing the central tendency.