Question

A student takes an exam containing 15 true or false questions. If the student guesses, what is the probability that he will get exactly 4 questions right? Round your answer to four decimal places.

Answer 1

Answer:

Given that:

A student takes an exam containing 15 true or false questions. If the student guesses, what is the probability that he will get exactly 4 questions right?

There are two options for each question. TRUE and FALSE

So , P(Getting question RIGHT ) = 1/4 = 0.25

p = 0.25

Now , there are 15 questions in the exam.

n = 15

Let X be the number of the right questions .

X follows Binomial(15 , 0.25)

Using binomial probability formula ,

P(X = x) = (ⁿ C _x)

P(get exactly 4 questions right)