Independent solution

How to solve this Expected Value question

Answer in brief

The expected unreduced loss is 30(0.01)+10(0.05)=0.80. A target profit of 0.25 from a premium of 1 leaves 0.75 for expected reimbursement, so the reimbursement share is 0.75/0.80=0.9375, choice E.

Setup

Setup

Let F and L count the two covered event types, and let q be the constant share reimbursed.

E[F]=0.01,E[L]=0.05\mathbb{E}[F]=0.01,\qquad \mathbb{E}[L]=0.05

Model

Model

Linearity of expectation gives the expected gross loss without requiring any dependence assumption between the event counts.

E[30F+10L]=30E[F]+10E[L]\mathbb{E}[30F+10L]=30\mathbb{E}[F]+10\mathbb{E}[L]

Compute

Compute

Set premium less expected reimbursement equal to the target profit and solve for q.

E[30F+10L]=30(0.01)+10(0.05)=0.80\mathbb{E}[30F+10L]=30(0.01)+10(0.05)=0.80
1q(0.80)=0.251-q(0.80)=0.25
q=0.750.80=0.9375q=\frac{0.75}{0.80}=0.9375

Answer

Answer

The company should reimburse 93.75% of each covered loss.

q=0.9375(E)\boxed{q=0.9375\quad\text{(E)}}