Jan 15'24
Exercise
Jan 15'24
Answer: E
[[math]]
\begin{aligned}
& e_{75: 10}=\int_{t=0}^{t=10}{ }_{t} p_{75} d t \quad \text { where }{ }_{t} p_{x}=\frac{{ }_{t+x} p_{0}}{{ }_{x} p_{0}}=\frac{1-\frac{(t+x)^{2}}{10000}}{1-\frac{x^{2}}{10000}}=\frac{10000-(t+x)^{2}}{10000-x^{2}} \text { for } 0\lt t \lt100-x \\
& =\int_{0}^{10} \frac{10000-75^{2}-150 t-t^{2}}{10000-75^{2}} d t \\
& =\frac{1}{4375} \cdot\left[4375 t-75 t^{2}-\frac{t^{3}}{3}\right]_{t=0}^{t=10}=8.21
\end{aligned}
[[/math]]