Back to Calculate the expected value of a random variable — Problem 4 · Task Set 28
Exercises: Calculate the Expected Value of a Random Variable
Work through each section in order. Compute expected value with $E(X) = \sum x \cdot P(X = x)$: multiply each value by its probability, then add. Show each term as "value times its probability" before summing. For payoff problems, write losses as negative values. Remember that $E(X)$ is the mean of the distribution and need NOT be a value the variable can actually take.
Grade 11·22 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-md-a-2
Work through problems with immediate feedback
A
Fluency Practice
Compute each expected value as an explicit weighted sum. Write each term as value times its probability before adding.
1.
A carnival game pays out an amount per play according to the distribution below.
| (dollars) | 0 | 2 | 5 |
|---|---|---|---|
| 0.6 | 0.3 | 0.1 |
If a player plays this game many, many times, what is the long-run average payout per play (in dollars)? Compute .