Find the standard deviation of the following binomial probability experiment:

Question

Find the standard deviation of the following binomial probability experiment:
A student guesses at all four multiple choice questions on a quiz where there are five choices for each question. There is only one of the choices in each question that is correct.

Answer 1

This is the Binomial Distribution with n=4 and p=1/5.

 

Standard deviation:

 

σ = √[np(1-p)] = √[(4)(1/5)(4/5)] = √(16/25) = 4/5 = 0.8