If the probabilities of a random variable $X$ assuming only two values $-3$ and $6$ are $\frac{1}{3}$ and $\frac{2}{3}$ respectively, what is the expected values of $X$ ?
If $p\left(x_j\right)$ are the probabilities of values $x_j$ of the variable $X$ for a discrete probability distribution, which of the following statements is true ?