Question

In 1970, the global human population was 3.71 billion people. The average global birth rate at that time was 3.1 per 100 individuals per year (0.031 per capita), and the average death rate was 1.0 per 100 individuals per year. What was r (r=per capita growth rate) for the human population at that time?

Answer 1

Growth rate per individual per year is calculated as :

r = birth rate per individual per year - the death rate of per individual per year

(Note individual & capita are the same in meaning)

The average global birth rate at that time was 3.1 per 100 individuals per year (0.031 per capita)

birth rate = 0.031

The average death rate was 1.0 per 100 individuals per year.

death rate = 1/100 = 0.01

r (per capita growth rate) for the human population at that time

= birth rate - death rate   

= 0.031 - 0.01

= 0.021

r = 0.021

0.021  per capita growth rate for the human population at that time.