(i)[1]
Show that $P(X = -2)$ and $P(X = 2)$ are the same.
(ii)[3]
Draw up the probability distribution table for $X$ in terms of $k$, and determine the value of $k$.
(iii)[2]
Find the value of $\text{E}(X)$.
Mathematics 9709 · AS & A Level · Linear combinations of random variables
Linear combinations of random variables — practice question
In this probability distribution, the random variable $X$ takes the value $x$ with probability $kx^2$, where $k$ is a constant, and the only values that $x$ can have are $-2, -1, 2, 4$.