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IAI Actuarial Core Principles · Risk Modelling and Survival Analysis · Transition intensities dependent on age (exact or census)

In a two-state model, μ_{x+t} = 0.001 + 0.0001t for t ≥ 0 (t in years, from age x). What is the 10-year survival probability from age x, to 4 decimal places?

The 10-year survival probability is e^(-0.015), about 0.9851, because the integrated force over ten years is 0.01 plus 0.005. Using only the constant part gives 0.9900, which ignores the rising term.

  1. A0.9851Correct
  2. B0.9900
  3. C0.9802
  4. D0.9753
  5. 0.9950

Explanation

Integral of μ from 0 to 10 = 0.001x10 + 0.0001x(100/2) = 0.01 + 0.005 = 0.015. Survival = e^(-0.015) = 0.98511. Option 1 uses only the constant term (e^-0.01). Option 2 doubles the integral wrongly.

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