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Suppose that the probability of having a particular disease is 0.08. Suppose that the probability of testing positive for the disease is 0.94 given that a person has the disease and 0.08 given that the person does not have the disease. Given that a person tests positive for the disease, what is the probability that they actually have the disease? (Answer to four decimal places).

User Anupam
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1 Answer

5 votes

Answer:

0.5054

Explanation:

This is a question on conditional probability.

We solve using Baye's Theorem of conditional probability

From the question

The probability of having a particular disease = 0.08.

The probability of not having a particular disease = 1 - 0.08 = 0.92

The probability of testing positive for the disease is given that a person has the disease = 0.94

The probability of testing positive given that the person does not have the disease = 0.08

Given that a person tests positive for the disease, the probability that they actually have the disease is

= (0.08 × 0.94)/(0.08 × 0.94) + (0.08 × 0.92)

= 0.0752/0.0752 + 0.0736

=0.0752/ 0.1488

= 0.5053763441

≈ Approximately to 4 decimal places = 0.5054

User Herpderp
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