Excelsior MAT101 Module 8 Problem Write-up

Based on what you learned from the problem you solved with your group, you will submit a written report describing your solution to a similar problem, posted as an Announcement on the first day of this module.  (Note link will not work until Announcement is posted).

The report is due on the last day of the module (Sunday at 11:59pm).

You may review textbook examples and use ideas from the discussion board, but you are expected to write your solution using your own words to explain your reasoning.  Please review M1A0: Academic Integrity Agreement and remember that you may not consult any other outside sources.

The report should be no more than 3 pages.

Keep the following in mind to maximize credit for your write-up:

Review the rubric your instructor will use to score your work. (See Evaluation Criteria below).

Answer all parts of the problem.

Write your solution in your own words. Show your justification for every step in your solution, using clear, mathematically accurate language. You can use phrases to explain your reasoning from step to step, but clearly state your final conclusions using complete English sentences (for example, “Jill needs to add 43 gallons of water to her pool”).

Label all numbers with the units they represent (e.g., 0.3048 ft/meter).

Type your write-up in MS Word and try to use the Equation Editor so that your equations are clear.

The video How to use Equation Editor in Microsoft Office (Links to an external site.) is a good tutorial. For this course, it is sufficient to watch segments 0:00-5:00 and 9:50-12:00. To cancel units, you can use the MS Word strikethrough feature (circled in blue below). Select what you want to cross out, and then click the strikethrough.

image of MS Word strikethrough feature circled in blue

Example:

28 yards times (0.9144 meters / 1 yard) = 25.6 meters. Both instances of the unit “yards” is crossed out to indicate cancellation.

This level of typesetting is also acceptable:

(28 yards) x 0.9144 meters/ 1 yards = 25.6 meters

Compose your work in a .doc or .docx file type using a word processor (such as Microsoft Word, etc.) and save it frequently to your computer. For those assignments that are not written essays and require uploading images or PowerPoint slides, please follow uploading guidelines provided by your instructor.

Check your work and correct any spelling or grammatical errors. When you are ready to submit your work, click “Upload Submission.” Enter the submission title and then click on “Select a file to upload.” Browse your computer, and select your file. Click “Open” and verify the correct file name has appeared next to Submission File. Click on “Continue.”  Confirm submission is correct and then click on “Accept Submission & Save.

Module 8

The problem you must solve is:

Consider a common disorder, which we will call Z, that affects 19% 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 50,000 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 positive 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 results actually have the disease?

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

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.