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 $\text{E}(X)=3$.

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