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A certain disease has an incidence rate of 0.6%. If the false negative rate is 4% and the false positive rate is 4%, computethe probability that a person who tests positive actually has the disease.Give your answer accurate to at least 3 decimal places. (13 decimal places)

User Alexkrishnan
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1 Answer

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23 votes

Given:

A certain disease has an incidence rate 0.6%. If the false negative rate is 4% and the false positive rate is 4%.

To know:

Probability that a person who tests positive actually has the disease.

Step-by-step explanation:

We can use Bayes theorem to calculate.

Solution:


\begin{gathered} P\left(disease\left|positive\right?\right)=(\left(0.006\right)\left(0.96\right))/(\left(0.006\right)\left(0.96\right)+\left(0.994\right)\left(0.04\right)) \\ \approx0.126 \end{gathered}

Hence 0.126 is the required probability.

User CrisisGriega
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