Original practice · fully worked
Original variant: expected payment under a mixed deductible
A repair loss is uniformly distributed from 0 to 10. Independently of the loss, a service contract uses a deductible of 2 with probability 0.40 and a deductible of 6 with probability 0.60. The contract pays the loss above the selected deductible. Calculate the expected payment.
- A
0.800 - B
1.280 - C
1.760 - D
2.000 - E
3.200
Answer and calculation
The expected payments under deductibles 2 and 6 are 3.2 and 0.8. Weighting them by probabilities 0.40 and 0.60 gives 1.76, choice C.
Setup
Setup
Use the uniform stop-loss formula at each possible deductible.
E[(X−d)+]=20(10−d)2,0≤d≤10 Model
Model
Evaluate the two conditional expected payments.
E[Y∣D=2]=2082=3.2 E[Y∣D=6]=2042=0.8 Compute
Compute
Average the conditional payments over the independent deductible selection.
E[Y]=0.40(3.2)+0.60(0.8) E[Y]=1.28+0.48=1.76 Answer
Answer
The expected contract payment is 1.760.
1.760(C)