4. Statistics and Probability

Mean And Variance Of A Distribution — Quiz

Test your understanding of mean and variance of a distribution with 5 practice questions.

Practice Questions

Question 1

What is the mean of the discrete distribution given by $X \in \{0,1,2\}$ with probabilities $P(X=0)=0.2$, $P(X=1)=0.5$, and $P(X=2)=0.3$?

Question 2

A random variable has mean $\mu=4$ and variance $\sigma^2=9$. What is the standard deviation?

Question 3

Which formula gives the variance of a discrete random variable $X$ with mean $\mu$?

Question 4

For the distribution $P(X=1)=0.25$, $P(X=3)=0.50$, and $P(X=5)=0.25$, what is the mean?

Question 5

A distribution has values $0$, $1$, and $2$ with probabilities $0.5$, $0.3$, and $0.2$ respectively. What is $E(X^2)$?