4. Statistics and Probability

Expected Value — Quiz

Test your understanding of expected value with 5 practice questions.

Practice Questions

Question 1

A random variable $X$ takes the value $2$ with probability $0.3$ and the value $5$ with probability $0.7$. What is $E(X)$?

Question 2

Which expression gives the expected value of a discrete random variable?

Question 3

A game costs $2$ to play. You win $10$ with probability $0.2$ and $0$ otherwise. What is the expected net gain per play?

Question 4

A player gets $3$ points for a head and loses $1$ point for a tail on a fair coin toss. What is the expected number of points per toss?

Question 5

On a test, a student scores $60$ with probability $0.25$ and $80$ with probability $0.75$. What is the expected score?