Question

Nathan had an infection, and his doctor wanted him to take penicillin. Because Nathan’s father and paternal grandfather were allergic to penicillin, Nathan has a 75% chance of having the same allergy. The doctor performed a skin test to see whether Nathan would react to it. The test is 98% accurate. If the test predicts that Nathan is not allergic to penicillin, what is the probability after the test that Nathan is not allergic to the drug?
Answer choices:
0.1135

0.2450

0.9423

0.9932

Answer 1

@jim_thompson5910

Answer 2

sorry still thinking

Answer 3

its okay @jim_thompson5910

Answer 4

this sounds too simple, but it might be correct

He has a 75% chance of being allergic, so 100-75 = 25% of not being allergic

The probability of not being allergic and having an accurate test at the same time is: 0.25*0.98 = 0.2450