Question

Sam is testing the effectiveness of a new cough medication. There are 100 people with a cough in the study. Thirty patients received the cough medication, and 70 other patients did not receive treatment. Seventeen of the patients who received the medication reported no cough at the end of the study. Twenty-eight of the patients who did not receive medication reported no cough at the end of the study. What is the probability that a patient chosen at random from this study took the medication, given that they reported no cough?

Answer 1

The probability of getting medication:

= 30/100

The probability of receiving no medication :

= 70/100

The probability of reporting no cough after receiving medication:

= 17/30

The probability that a patient chosen at random receives medication and reports no cough is :

= 17/30 × 30/100 = 17/100

= 17/100 = 0.17