Hashini Wickramasuriya
Made first post
Question:
An insurance company believes that claim amounts in a certain portfolio of policies
follow a normal distribution. An analyst chose 61 policies at random which gave a
sample mean of £523 and a sample standard deviation of £81.
The company assumes that the true mean and standard deviation of claim amounts are
the same as those in the sample.
The number of claims per month for the portfolio follows a Poisson process with
mean 250.
(iv) Determine the mean and standard deviation for the total annual amount of
claims in the portfolio.
Answer in the examiner's report:
(iv) Now the rate of claims is 12 × = 3000 [1]
Mean = _new * mu_claims = 3000 ∗ 523 = 1,569,000 [1]
Standard deviation = sqrt(lamda_annual) * sqrt(sigma_claim^2+mu^2)
= √3000 ∗ √(812 + 5232) =28987 [2]
can anyone explain how the standard deviation is calculated?
An insurance company believes that claim amounts in a certain portfolio of policies
follow a normal distribution. An analyst chose 61 policies at random which gave a
sample mean of £523 and a sample standard deviation of £81.
The company assumes that the true mean and standard deviation of claim amounts are
the same as those in the sample.
The number of claims per month for the portfolio follows a Poisson process with
mean 250.
(iv) Determine the mean and standard deviation for the total annual amount of
claims in the portfolio.
Answer in the examiner's report:
(iv) Now the rate of claims is 12 × = 3000 [1]
Mean = _new * mu_claims = 3000 ∗ 523 = 1,569,000 [1]
Standard deviation = sqrt(lamda_annual) * sqrt(sigma_claim^2+mu^2)
= √3000 ∗ √(812 + 5232) =28987 [2]
can anyone explain how the standard deviation is calculated?