Excelsior College Mathematics for Everyday Life Problem Questions

Description

The problem you must solve is:

Consider a common disorder, which we will call Z, that affects 20% of adults (18 years and over) in the U.S. Fortunately, there is a genetic screening test for the gene that causes disorder Z. The test is 98% accurate; that is, 98% of the people who take the test get the correct result (and 2% of people tested get the wrong result).

In Johnsonville, the adult population is 120,000 and all the residents get tested for the gene linked to disorder Z.

  1. How many of the residents of Johnsonville are likely to have the disease?
  2. How many of the people who actually have the disease get a positive test result?
  3. How many of the people who do not have the disease get a negative test result?
  4. Of the people who get a positive test result, how many of them have the disease?Convert this to a percentage: What percent of people who get a positive test resultsactually have the disease?
  5. How many residents will NOT have the disease but test positive? Convert this to apercentage: What percentage of residents will NOT have the disease but test positive?

6. Compare your results with the problem you solved in the discussion activity (M8D1). Be

careful not to just re-state the results from each…Specifically, focus on the percent of

people who get a positive result that actually have the disease. Remember that both

genetic tests were 98% accurate. Why were the percentages so different? Do you think

the rarity of the disease affects testing results? Why or why not? Be sure to explain

your reasoning mathematically.