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Back to Analyze decisions and strategies using probability — Problem 2 · Task Set 34

Exercises: Analyze Decisions and Strategies Using Probability

Work through each section in order. For testing problems, build the two-way table over the stated population and compute the decision-relevant quantity by counting. Remember the difference between a test's accuracy P(positive | disease) and the decision-relevant P(disease | positive). For strategy problems, account for how a choice changes ALL of the probabilities, not just the one you want. Write explanation answers in complete sentences and name your assumptions.

Grade 12·20 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-md-b-7
Work through problems with immediate feedback
A

Fluency Practice

Compute the decision-relevant quantity in each problem.

1.

A disease has prevalence 1%1\% in a population of 10,00010{,}000 people, so 100100 have it and 9,9009{,}900 do not. A test is 99%99\% sensitive (catches 9999 of the 100100 sick) and 99%99\% specific (correctly clears 99%99\% of the healthy). How many of the 9,9009{,}900 healthy people test positive (false positives)?