A claim was recently made on national television that two of every three doctors recommend a particular pain killer. Suppose a random sample of n = 300 doctors revealed that 180 said that they would recommend the painkiller. If the TV claim is correct, what is the probability of 180 or fewer in the sample agreeing?
A) 0.4929
B) 0.0049
C) 0.9929
D) 0.0142

Question

Quizplus · Accepted Answer

The claim suggests that 2/3 of doctors recommend the painkiller, so the expected number in a sample of 300 is 200. Using a normal approximation to the binomial distribution, the probability of observing 180 or fewer is calculated to be approximately 0.0049.

A Claim Was Recently Made on National Television That Two