Question

please help solve this.

Ecology is the subject

Open Problem #3 Spreadsheet. In 1981, the world human population was 4.5 billion. The birth rate was 28 per thousand (0.028 per capita) and the death rate, 11 per thousand (-0.011) Thus the r value was 0.017. Using these figures, project the population for 30 years to 2011. What is the expected human population based on the above figures (Just use 4.5 for No)? Compare this value with 2011current population of 69 billion. This shows that population growth has slowed since 1981. Why? Make sure you can solve this problem with your hand calculator because you need to for the exam

Answer 1

Ans

There is an increase of 17 people per thousand in a particular year.

Which means 17/1000 increase. Hence rate of increase is 1.7% per year.

As this increase would be on the increased population. Hence the population has to be compounded annually.

So the increase can be calculated as

Future Population = Present Population ( 1 + Rate of increase in population ) ^ ^{No of future years}

Future Population = 4.5 ( 1 + 1.7%)³⁰

Future Population = 4.5 (1.65)

Future Population in 2011 ( Expected )= 7.46 Billion

Actual Population in 2011 = 7 Billion

Hence we can say that the rate of population has decreased a bit since 1981.