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CanadaON
Grade 12

EXT: Mean and variance of Linear combinations of CRV

Interactive practice questions

A uniform probability density function, $P\left(x\right)$P(x), is positive over the domain $\left[20,50\right]$[20,50] and $0$0 elsewhere.

a

State the function defining this distribution.

$P\left(x\right)$P(x) $=$= $\editable{}$ if $\editable{}\le x\le\editable{}$x
$\editable{}$ for all other values of $x$x
b

Use integration to determine the expected value of the distribution.

c

Use integration to determine the variance $V\left(X\right)$V(X) of the distribution.

d

The distribution is transformed to the random variable $Y$Y by $Y=2X+4$Y=2X+4. Calculate $E\left(Y\right)$E(Y), the expected value of $Y$Y.

e

Determine the variance $V\left(Y\right)$V(Y) of the random variable $Y$Y as defined by $Y=2X+4$Y=2X+4.

f

Determine the standard deviation $SD\left(Y\right)$SD(Y) of $Y$Y.

Round your answer to one decimal place.

Easy
11min

A continuous random variable $X$X has a uniform probability density function over the domain $\left[10,80\right]$[10,80].

$X$X is transformed to the random variable $Y$Y by $Y=2X+3$Y=2X+3.

Easy
1min

Consider the graph of the probability density function $P\left(x\right)$P(x) shown.

Easy
13min

Consider the graph of the probability density function $P\left(x\right)$P(x) shown.

Easy
10min
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