Question

(Please use a separate piece of paper to calculate the answer for this problem.) A study to determine the sensitivity and specificity of a new test for macular degeneration is conducted on 2430 people. Macular degeneration occurs at a rate of 16.72 percent. Your sample has the same prevalence of macular degeneration. You find that 377 people with macular degeneration tested positive with the new test. You also have a total of 561 positive test results in your study. CALCULATE THE POSITIVE PREDICTIVE VALUE of this test under these circumstances. Group of answer choices 83.29% 98.45% 67.20% 92.86% 23.09%

Answer 1

`67.20\%`

Explanation:

Given

`n =2430` --- sample

`r = 16.72\%` --- degeneration rate

From the findings, we have:

`p = 377` --- tested positive

`t =561` --- total test

Required

The positive predicted value (PPV)

This is calculated using:

`PPV=(Positive)/(Total)`

i.e.

`PPV = (377)/(561)`

`PPV = 0.6720`

Express as percentage

`PPV = 0.6720 * 100\%`

`PPV = 67.20`