Expected Value E00A2D
1. The problem is to find the expected value $E(X)$ and the variance $\mathrm{Var}(X)$ of a random variable $X$ given its probability distribution.
2. The expected value formula is:
$$E(X) = \sum x P(x)$$
where $x$ are the values of the random variable and $P(x)$ are their probabilities.
3. From the problem, we have:
$$E(X) = \frac{1}{6}(20 + 40 - 30) = \frac{1}{6} \times 30 = 5$$
4. The variance formula is:
$$\mathrm{Var}(X) = E(X^2) - [E(X)]^2$$
where $E(X^2)$ is the expected value of the square of $X$.
5. To find $\mathrm{Var}(X)$, we need $E(X^2)$, which is not given here, so we cannot compute the variance without additional information.
6. Summary:
- Expected value $E(X) = 5$
- Variance $\mathrm{Var}(X)$ cannot be computed without $E(X^2)$