Fall Semester, 2010
Chapter Ten Homework
Assignment due on Tuesday, November 16, 2010
Problems: Example examination problems 1 and 2 below, and 10.6, 10.19, 10.54, 10.59,
10.63, Actuarial Examination Practice problem below, and the two example examination
10.6. A test was developed in the 1980s for screening donated blood for the presence of HIV.
The test is designed to detect antibodies, substances produced in the body of donors carrying the
virus; however, the test is not 100% accurate. The developer of the test claimed that the test
would produce fewer than 5% false positives and fewer than 1% false negatives. In order to
evaluate the accuracy of the test, 1,000 persons known to have HIV and 10,000 persons known
to not have HIV were given the test. The following results were tabulated.
Does Not Have HIV
Place a 95% confidence interval on the proportion of false positives produced by the test.
Is there substantial evidence (
) that the test produces less than 5% false positives?
10.19. The media selection manager for an advertising agency inserts the same advertisement for
a client bank in two magazines, similarly placed in each. One month later, a market research
study finds that 226 of 473 readers of the first magazine are aware of the banking services
offered in the ad, as are 165 of 439 readers of the second magazine (readers of both magazines