- 1. It took 1649 years for the world population to double, going from .25 billion people to .50 billion people. How long did it take for the population to double once again? 100 years (from 1750 to 1850)
- 2. How long did it take for the population to double a second time? 100 years (from 1850 to 1950) A third time? 47 years (from 1950 to 1997, approximated from 1956 to 2004 data: 2.5 to 6.5 billion is more than double; 2.5 to 5.0 would be double, which occurred around 1980–1981, so ~24–25 years from 1956, but since the question likely expects doubling from 1 billion to 2 billion, then 2 billion to 4 billion, then 4 billion to 8 billion — we adjust: from 1 billion (1850) to 2 billion (1925) = 75 years; from 2 billion (1925) to 4 billion (1976) = 51 years; from 4 billion (1976) to 8 billion (not yet reached by 2012, projected ~2023–2025) = ~47–49 years from 1976. But based strictly on given data points: from 1.0 to 2.0 (1850–1925) = 75 years; from 2.0 to 4.0 (1925–1976) = 51 years; from 4.0 to 8.0 (extrapolated) — not in table, so answer based on available: second doubling (1→2) = 75 years, third doubling (2→4) = 51 years.
- 3. Use a different color to extend your graph to the year 2015. In what year will the population reach 10 billion? Approximately 2050–2060 (based on extrapolation of trend; UN projections suggest ~2058–2060).
- 4. Based on your graph, how many years will it take for the population of 2000 to double? From 6.0 billion in 2000 to 12.0 billion — extrapolating exponential growth, approximately 40–50 years (around 2040–2050), though actual projections vary.
- 5. The graph illustrates exponential growth. Based on the properties of this graph, what does this term mean? Exponential growth means the population increases at an accelerating rate over time — each doubling occurs in less time than the previous one, resulting in a J-shaped curve on the graph.
Parent Tip: Review the logic above to help your child master the concept of population growth worksheet.
