A multiple-choice test has 30 questions. There are 4 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

A binomial distribution can be used to model the number of successes in a fixed number of independent trials, where each trial has two possible outcomes (in this case, either getting the question right or wrong) and the probability of success is the same for each trial. The conditions for using a binomial distribution are met in this scenario, so it is the appropriate choice.

A Multiple-Choice Test Has 30 Questions