Functions of a DRVAQA A-Level Further Maths: Mind map

Exam questions on Functions of a DRV

1. The discrete random variable $X$ takes the values $1,2,3$ with $P(X=1)=0.2$, $P(X=2)=0.5$ and $P(X=3)=0.3$.
   Find $E(5X^3)$.2 marks
2. The discrete random variable $X$ takes the values $1,2,4$ with $P(X=1)=0.4$, $P(X=2)=0.4$ and $P(X=4)=0.2$.
   Hence find $\mathrm{Var}(6X^{-1})$.2 marks
3. The discrete random variable $X$ has probability distribution $P(X=x)=\frac{x}{10}$ for $x=1,2,3,4$.
   Find $E(18X^{-3})$.3 marks