8.1.1—Population inputs
- Syllabus
- First assessment 2026
- Objective
- 8.1.1
- Level
- SL
Inputs Add People
Births and immigration add people to a population; a crude input rate makes the count comparable across populations of different sizes.
Use events ÷ total population × 1,000 when the question asks for a rate per 1,000 per year. Births happen inside the population; immigration crosses its boundary from outside.
25,000 births in 500,000 people gives (25,000 ÷ 500,000) × 1,000 = 50 births per 1,000 people.
50 per 1,000: (2,000 ÷ 40,000) × 1,000.
2,000 is an event count, not a rate. A rate needs the population denominator and its units.