(a)[1]
Write down $k$ in terms of $a$.
(b)[4]
Given that $\mathrm{Var}(X) = 3$, determine $a$.
Mathematics 9709 · AS & A Level · Linear combinations of random variables
Linear combinations of random variables — practice question
The diagram illustrates the probability density function, $f(x)$, for a random variable $X$. When $0 \leq x \leq a$, $f(x) = k$; for all other values, $f(x) = 0$.