4. Probability, Random Variables, and Probability Distributions

Combining Random Variables — Quiz

Test your understanding of combining random variables with 5 practice questions.

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Practice Questions

Question 1

If $X$ and $Y$ are random variables, what does $E(X+Y)$ equal in general?

Question 2

If a random variable $X$ is multiplied by a constant $c$, what is the expected value of $cX$?

Question 3

A fair coin is flipped twice. Let $X$ be the number of heads on the first flip and let $Y$ be the number of heads on the second flip. What is $E(X+Y)$?

Question 4

If $X$ and $Y$ are independent random variables, what is the variance of $X+Y$?

Question 5

A student's quiz score is modeled by $T=A+B$, where $A$ is the score on part 1 and $B$ is the score on part 2. Which statement is always true?