Questions from Statistics

Q: Suppose a test for a disease is 80% accurate for those

Suppose a test for a disease is 80% accurate for those who have the disease (true positives) and 80% accurate for those who do not have the disease (true negatives). Within a sample of 4000 patients,...

Q: (This problem is based on an example in the column “

(This problem is based on an example in the column “Ask Marilyn” in Parade magazine.) A company decided to expand, so it opened a factory, generating 455 jobs. For the 70 white-collar positions, 200 m...

Q: (This problem is based on an example from the column “

(This problem is based on an example from the column “Ask Marilyn” in Parade magazine.) A company runs two trials of two treatments for an illness. In the first trial, Treatment A cures 20% of the cas...

Q: The 95% confidence interval for a poll suggested that support for

The 95% confidence interval for a poll suggested that support for Governor Garcia is between 55% and 60%. Therefore, we can be certain that a majority of the population supports the governor.

Q: The sexuality of women was discussed in Shere Hite’s book Women and

The sexuality of women was discussed in Shere Hite’s book Women and Love: A Cultural Revolution in Progress. Her conclusions were based on sample data from 4500 mailed responses obtained from 100,000...

Q: The New York State Department of Health estimates a 10% rate

The New York State Department of Health estimates a 10% rate of HIV infection among the at-risk population and a 0.3% rate in the general population. Tests for HIV are 95% accurate in detecting both t...

Q: Professional athletes are routinely barred from participation for using banned substances.

Professional athletes are routinely barred from participation for using banned substances. For such a test, what is a false positive? What is a false negative? What is a true positive? What is a true...

Q: When constructing a histogram of blood platelet counts, it is better

When constructing a histogram of blood platelet counts, it is better to use three-dimensional bars in the graph.

Q: A professional soccer player is given a test for a banned substance

A professional soccer player is given a test for a banned substance. What does it mean when she is told that the result is positive? Do we know from such a positive result whether the player actually...

Q: If you are pulled over while driving and given a breathalyzer test

If you are pulled over while driving and given a breathalyzer test for alcohol, what is the result called if the test incorrectly indicates that you have consumed alcohol?