86.0k views
5 votes
A calculus student takes a 20-question, multiple choice test with 5 answer choices for each question. find the mean and standard deviation of the number of questions that he/she gets correct

User Tom Maton
by
8.5k points

1 Answer

0 votes
Suppose the student guesses the answers, we shall consider this a binomial probability problem of success. This implies that getting a question right is p=1/5.
The number of questions is n=20 questions.
The mean of binomial distribution is
mean=n*p= 20*1/5=4

b] The standard deviation of a binomial distribution is given by:
σ=√(n*p*(1-p))
=√(20*0.2*0.8)
=1.79~1.8

Answer:
μ=4 ; σ=1.8
User XVirtusX
by
9.1k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories