May 05'23

Exercise

The table below shows the joint probability function of a sailor’s number of boating accidents and number of hospitalizations from these accidents this year.

Number of Hospitalizations from Accidents
Number of Accidents 0 1 2 3
0 0.700
1 0.150 0.050
2 0.060 0.020 0.010
3 0.005 0.002 0.002 0.001

Calculate the sailor’s expected number of hospitalizations from boating accidents this year.

  • 0.085
  • 0.099
  • 0.410
  • 1.000
  • 1.500

Copyright 2023. The Society of Actuaries, Schaumburg, Illinois. Reproduced with permission.

May 05'23

Solution: B

The marginal distribution for the probability of a given number of hospitalizations can be calculated by adding the columns. Then p(0) = 0.915, p(1) = 0.072, p(2) = 0.012, and p(3) = 0.001. The expected value is

0.915(0) + 0.072(1) + 0.012(2) + 0.001(3) = 0.099.

Copyright 2023. The Society of Actuaries, Schaumburg, Illinois. Reproduced with permission.

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