A multiple-choice test has 30 questions.There are four choices for each question.A student who has not studied for the test decides to answer all questions randomly.What type of probability distribution can be used to figure out his chance of getting at least 20 questions right?
A) Binomial distribution.
B) Poisson distribution.
C) Hypergeometric distribution.
D) None of the above.

Question

Quizplus · Accepted Answer

The binomial distribution can be used to calculate the probability of getting at least a certain number of successes in a fixed number of independent trials, where each trial has the same probability of success. In this case, each question is an independent trial with a probability of success of 1/4 (the chance of getting the correct answer). Therefore, the binomial distribution can be used to calculate the probability of the student getting at least 20 questions right.

A Multiple-Choice Test Has 30 Questions