Question

Bobby is testing the effectiveness of a new cough medication. There are one hundred people with a cough in the study. Seventy patients received the cough medication and thirty other patients did not receive treatment. Thirty-four of the patients who received the medication reported no cough at the end of the study. Twenty 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

I keep getting 69.4% which is not an answer choice

Answer 2

I did P(A)=.7
P(A&B)=.486
P(B|A)=.486/.70=.694

Answer 3

refer to this one to help u http://openstudy.com/study#/updates/5277f8aee4b0ebf890293ca8

Answer 4

scroll all the way down

Answer 5

Thirty-four of the patients who received the medication reported no cough
Twenty of the patients who did not receive medication reported no cough

so 34+20 = 54 reported no cough
the probability of receiving the med is 34 out of 54

Answer 6

using formulas, label A as taking med, B as "no cough"
\[ P(A | B) = \frac{P(A \cap B)}{P(B)}\]

Pr(B) = Pr(no cough) = 54/100= 0.54
Pr of reporting no cough and taking the med is 34/100 = 0.34

Answer 7

Thanks @chris911 and @phi I got 62.96% as my final answer. Is that correct?

Answer 8

yes, that is what I get.

Answer 9

Thank you :)

Answer 10

yw

Answer 11

yep