A multiple choice quiz consists of 50 questions, each with 4 possible answers. Find the mean for the number of correct answers, if a student guesses on each question.
A) 25.0
B) 12.5
C) 4.0
D) 46.0

Question

Quizplus · Accepted Answer

Since there are 4 possible answers for each question, the probability of guessing the correct answer is 1/4. Therefore, the expected value for the number of correct answers on a single question is 1/4. Since there are 50 questions, the expected value for the total number of correct answers is:
Expected value = (1/4) x 50 = 12.5
Therefore, the mean for the number of correct answers, if a student guesses on each question, is 12.5.

A Multiple Choice Quiz Consists of 50 Questions, Each with 4