| Tag | Value |
|---|---|
| file | Probability_uva-expected-value-763-en_uva-expected-value-763-en |
| name | uva-expected-value-763-en |
| section | Probability/Elementary Probability/Random variables/Expected value |
| type | num |
| solution | 1.2 |
| tolerance | 0 |
| Type | Calculation |
| Language | English |
| Level | Statistical Literacy |
| IRT-Difficulty | 5.144 |
| p-value | 0.0088 |
A closed box contains five balls: three red and two yellow. You pick two balls at the same time at random. Suppose the random variable X is the number of red balls and X can take the values 0,1 and 2. What then is the expectation value of X?
The correct answer is: 1.2