# and it is theretorevery important to obtain some estimate of disease prevalence.ExercisesA medical research team wishes to assess the usefulness of a certain symptom (call it S) inthe diagnosis of a particular disease. In a random sample of 775 patients with the disease,744 reported having the symptom. In an independent random sample of 1380 subjectswithout the disease, 21 reported that they had the symptom.(a) In the context of this exercise, what is a false positive?(b) What is a false negative?(c) Compute the sensitivity of the symptom.(d) Compute the specificity of the symptom.(e) Suppose it is known that the rate of the disease in the general population is. 001. Whatis the predictive value positive of the symptom?(f) What is the predictive value negative of the symptom?(g) Find the predictive value positive and the predictive value negative for the symptomfor the following hypothetical disease rates: .0001, .01, and .10.(h) What do you conclude about the predictive value of the symptom on the basis of theresults obtained in part g?3.5.1 SOME BASIC PROBABILITY CONCEPTSIn an article entitled "Bucket-Handle Meniscal Tears of the Knee: Sensitivity and Speci-ficity of MRI signs," Dorsay and Helms (A-5) performed a retrospective study of 71 kneesscanned by MRI. One of the indicators they examined was the absence of the "bow-tiesign" in the MRI as evidence of a bucket-handle or "bucket-handle type" tear of the menis-cus. In the study, surgery confirmed that 43 of the 71 cases were bucket-handle tears. Thecases may be cross-classified by “bow-tie sign" status and surgical results as follows:3.5.2Tear Surgically ConfirmedTear SurgicallyConfirmed (D)As Not Present (D)Total381048Positive Test(absent bow-tie sign) (T)5Negative Test(bow-tie sign present) (T)182343Total2871Source: Theodore A. Dorsay and Clyde A. Helms, "Bucket-handle Meniscal Tears of the Knee: Sensitivity andSpecificity of MRI Signs," Skeletal Radiology, 32 (2003), 266–272.(a) What is the sensitivity of testing to see if the absent bow tie sign indicates a meniscaltear?(b) What is the specificity of testing to see if the absent bow tie sign indicates a meniscaltear?(c) What additional information would you need to determine the predictive value of thetest?

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we went over these problems in class for our notes in review for our up and coming exam, I've been out sick with the flu all week can you guys please help me

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Step 1

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Step 2

Given that,

In a random sample of 775 patients with the disease, 744 reported having the symptom. In an independent random sample of 1380 subjects without the disease, 21 reported that they had the symptom.

From the given details,

 Positive disease Negative disease total Positive test 744 21 765 Negative test 31 1359 1390 total 775 1380 2155
Step 3
1. In the context of this exercise, please describe what is a false positive?

The false positive would be a patient ...

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