(i)[1]
Find $p$.
(ii)[2]
With $\text{E}(X) = 1.15$ given, determine $\operatorname{Var}(X)$.
Mathematics 9709 · AS & A Level · Linear combinations of random variables
Linear combinations of random variables — practice question
A random variable $X$ is given by the probability distribution in the table below, with $p$ as a constant. The possible values are $x = -1, 0, 1, 2, 4$ and the corresponding probabilities are $P(X = -1) = p$, $P(X = 0) = p$, $P(X = 1) = 2p$, $P(X = 2) = 2p$, and $P(X = 4) = 0.1$.