Assume that guesses are made for 4 questions on a medical admissions test such that the probability of success (correct) is given by pequals0.30, where there are nequals4 tria…

Question

asked Jan 27, 2021 210k views

1 Answer

Jiahao · Answer 1 · 2021-02-03T04:41:54+0000

Answer:

0.2646 is the probability that exactly 2 questions are correctly answered.

Explanation:

We are given the following information:

We treat correct as a success.

P(success) = 0.30

Then the number of correct answers follow a binomial distribution, where

$P(X=x) = \binom{n}{x}.p^x.(1-p)^(n-x)$

where n is the total number of observations, x is the number of success, p is the probability of success.

Now, we are given n = 4

We have to evaluate:

$P(x =2)\\= \binom{4}{2}(0.30)^2(1-0.30)^2\\= 0.2646$

0.2646 is the probability that exactly 2 questions are correctly answered.