CAIE A Level Mathematics 9709 · Discrete random variables

Discrete random variables: calculation question

4 marksStandard

The discrete random variable $X$ has the probability distribution shown.

$x$	1	3	6
$\mathrm{P}(X = x)$	0.4	0.5	0.1

(a)
Find $\mathrm{Var}(X)$ .
[4]

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