Todo --- add to heavy tails lecture

[jstac]

Show how the CCDF of the Pareto distribution can be derived from the CCDF of the exponential distribution.

Add this as exercise-solution after definition of $G_E$ and $G_P$.

Derivation:

$$ \begin{aligned} G_P(y) & = \mathbb P{Y > y} \\ & = \mathbb P{\exp(X) > y} \\ & = \mathbb P{X > \ln y} \\ & = G_E(\ln y) \\ & = \exp( - \alpha \ln y) \\ & = y^{-\alpha} \end{aligned} $$

(Edit to get LaTeX code, copy and paste. For some reason curly brackets not rendering properly.)

Should be included in #182 or added after it is merged.

[jstac]

@shlff , could you please take care of this small task?