Question

There are five multiple choice questions on an exam, each having responses a, b, c,and d. Each question is worth 5 points, and only one option per question is correct. Suppose the student guesses the answer to each question, and these guesses, from question to question, are independent. The student's mean number of questions correct on the exam should be:

Answer 1

Answer:1.25

Explanation:

Given

There are four options to multiple choice question and only one is correct which will reward 5 points.

Using Binomial distribution to get the result since no of trials is finite

n=5

chances of guessing a correct question p=0.25

and mean for Binomial distribution is given by

`\mu =np`

`\mu =5* 0.25=1.25`