4. For a portfolio of risks, aggregated losses has a compound Poisson distribution, where the expected number of losses is 10, and loss distribution is exponential distribution with 0 = 100. To lower the insurance cost, the insurer removes one type of risk, which happens with probability 0.1, and imposes a deductible of 20 per loss. i) What is the expected aggregate amount paid by the insurer after this modification? ii) What is the approximate probability that the aggregate loss is larger than 500 after this modification