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Chapter 5: Q20P (page 115)

Olympic athletes are tested to see if they are using illegal performance-enhancing drugs. Suppose that urine samples are taken and analyzed and the rate of false positive results is 1 %. Suppose also that it is too expensive to refine the method to reduce the rate of false positive results. We do not want to accuse innocent people of using illegal drugs. What can you do to reduce the rate of false accusations even though the test always has a false positive rate of 1 %?

Short Answer

Expert verified

They should choose to increase the number of replicates for the test samples in order to dramatically reduce the occurrence of false positive errors.

Step by step solution

01

Definition of false positive rate

  • The false positive rate is the percentage of all negatives that result in positive test results, or the conditional probability of a positive test result in the absence of an event.
  • The significance level is equivalent to the false positive rate.
02

Determine to reduce the rate of false accusations and test always has a false positive rate of 1%

  • They should choose to increase the number of replicates for the test samples in order to dramatically reduce the occurrence of false positive errors.
  • If two independent samples are used in the test (for example, both drawn at the same time), the error can be reduced from 1% to 0.01 percent.

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