You are given the following survival function:

Calculate [math]1000 \mu_{25}[/math].

• 6.7
• 10.0
• 13.3
• 16.7
• 20.0

For a given population with two subgroups, you are given:

i) Subgroup [math]\mathrm{X}[/math] represents 80% of the total population and is subject to a constant annual force of mortality of 0.01

ii) Subgroup [math]\mathrm{Y}[/math] represents 20% of the total population and is subject to a constant annual force of mortality of 0.02

Calculate the proportion of the population 15 years from now that is part of subgroup [math]\mathrm{X}[/math].

• 80.0%
• 81.1%
• 82.3%
• 83.4%
• 84.6%