Exercise
Jan 18'24
Answer
Answer: E
Out of 400 lives initially, we expect [math]400_{25} p_{60}=400 \frac{l_{85}}{l_{60}}=400\left(\frac{61,184.9}{96,634.1}\right)=253.26[/math] survivors
The standard deviation of the number of survivors is [math]\sqrt{400_{25} p_{60}\left(1-{ }_{25} p_{60}\right)}=9.639[/math]
To ensure [math]86 \%[/math] funding, using the normal distribution table, we plan for [math]253.26+1.08(9.639)=263.67[/math]
The initial fund must therefore be [math]F=(264)(5000)\left(\frac{1}{1.05}\right)^{25}=389,800[/math].