Assume we have a risky event with a potential cost of damages, Xi, being lognormally distributed with mean = 7 variance = 5 :
Let us assume that an insurance covers n risky events. What is the expected value and standard deviation of X1 + X2 + ...+Xn if :
(iv) n = 10, correlation(Xi;Xj) = 0
(v) n = 100, correlation(Xi;Xj) = 0
这两小题的公式是什么?
(d) Suppose the insurance company needs to hold a risk margin on top of the central estimate of the insurance liability with respect to the portfolio of policies covering against this risky event, X1 + ...+Xn such that the probability of adequacy exceeds 0.75. How much provisions need to be held for the above cases?
我会用central limit theorem算sums &means, 但是前提是每个是independent的,如果有了correlation,公式是什么?