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Conditional Probability

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Question 83

The continuous random variable WWW represents the daily electrical energy produced by a specific solar array (in kWh) and has probability density function g(w)g(w)g(w) given by

g(w)={124w0≤w≤4164<w≤80otherwise g(w) = \begin{cases} \frac{1}{24}w & 0 \le w \le 4 \\ \frac{1}{6} & 4 < w \le 8 \\ 0 & \text{otherwise} \end{cases} g(w)=⎩⎨⎧​241​w61​0​0≤w≤44<w≤8otherwise​
a.

Sketch the graph of g(w)g(w)g(w).

[3]
b.

Determine the conditional probability P(2≤W≤6∣W≤7)P(2 \le W \le 6 \mid W \le 7)P(2≤W≤6∣W≤7).

[5]
c.

A secondary random variable VVV, representing daily ambient temperature in degrees Celsius, is such that E(V)=9E(V) = 9E(V)=9 and Var(V)=0.75Var(V) = 0.75Var(V)=0.75.

Calculate E(5V2−18W+7)E(5V^2 - 18W + 7)E(5V2−18W+7).

Show your working clearly. (Solutions relying on calculator technology are not acceptable.)

[5]

Conditional Probability Questions

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