Mathematics 9709 · AS & A Level · Continuous random variables
Continuous random variables — practice question
The probability density function, $f$, for the random variable $X$ is defined as
$f(x) = \begin{cases} k(6x - x^2), & 0 \leq x \leq 6, \\ 0, & \text{otherwise}, \end{cases}$
with $k$ as a constant.
(main)[6]
State the value of $\text{E}(X)$ and demonstrate that $\mathrm{Var}(X)=\frac{9}{5}$.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Take $\text{E}(X)=3$.” …