Exercise
ABy Admin
May 14'23
Answer
Key: B
Let S denote aggregate loss before deductible.
[[math]]
\operatorname{E}(S) = 2(2) = 4,
[[/math]]
since mean severity is 2.
[[math]]
f_S(0) = \frac{e^{-2}2^0}{0!} = 0.1353,
[[/math]]
since must have 0 losses to get aggregate loss = 0.
[[math]]
f_S(1) = \frac{}{} \frac{1}{3} = 0.0902,
[[/math]]
since must have 1 loss whose size is 1 to get aggregate loss = 1.
[[math]]
\begin{aligned}
&\operatorname{E}[ S \wedge 2) = 0 f S (0) + 1 f S (1) + 2[1 − f S (0) − f S (1)] \\
&= 0(0.1353) + 1(0.0902) + 2(1 − 0.01353 − 0.0902) = 1.6392 \\
&\operatorname{E}[(S − 2)+ ] = \operatorname{E}[ S ) − \operatorname{E}[ S \wedge 2) = 4 − 1.6392 = 2.3608
\end{aligned}
[[/math]]