Show My Work state medical school has discovered a new test for tuberclosa. ( th
ID: 3045634 • Letter: S
Question
Show My Work state medical school has discovered a new test for tuberclosa. ( the test naaas a person beats probability of a positive test is O.81 tuberculosis. Assume that in the general populatien, the probablity that a person has tubercuiosis is 0.06 following categories. (Enter your answers to four decimal places) has tuberculosis, the test is pesitive.) Experimentation has shown that the 1, given that a person has tuberculosis. The probability is o.o9 that the test registers postive, given that the person does not have . what i·th. probabley that . penon chosen at rar dem fali in (a) have tuberculosis and have a positive test (b) not have tuberculosis (e) not have tuberculosis and have a positive test Need Help? Show My Work in 888a 2 3Explanation / Answer
Solution :
We are given that P(positive test| Having tuberculosis) = 0.81
P(Having tuberculosis) = 0.06 and P( positive test| Not having tuberculosis) = 0.09
a) To find Probability that person have tuberculosis and positive test.
Using the conditional probability formula ,P(A|B) = P(A and B)/P(B)
=>P(A and B) = P(A|B)*P(B)
So here P( Having Tuberculosis and Positive test) = P(Positive test| Having tuberculosis) * P( having tuberculosis)
= 0.81*0.06 =0.0486
Therefore, Probability that person have tuberculosis and positive test = 0.0486
b) Probability that person choose at random do not have tuberculosis = 1 - P( having Tuberculosis) = 1- 0.06 = 0.94
c) Probability that person not have tuberculosis and test positive is same as P( test positive and not having tuberculosis)
Again using conditional probability formula, we get
P( test positive| not having tuberculosis) = P( test positive and not having tuberculosis)/P(not having tuberculosis)
So,P( test positive and not having tuberculosis)= P( test positive| not having tuberculosis)*P(not having tuberculosis)
= 0.09*0.94 = 0.0846