Question

the crude growth rate, r, of a population is calculated by
a. multiplying the existing population size by life expectancy
b. dividing the crude birth rate by 2
c. dividing the doubling time by 70
d. adding the crude birth rate to the crude death rate
e. subtracting the crude death rate from the crude birth rate

Explanation:

The crude growth rate (\(r\)) of a population is calculated as \(r=\text{crude birth rate}-\text{crude death rate}\). Option A is incorrect as population size and life expectancy don't relate to this formula. Option B is wrong; there's no basis for dividing crude birth rate by 2. Option C is for calculating doubling time (doubling time \(=\frac{70}{r}\), not the other way). Option D adds them, which is incorrect. Only Option E follows the correct formula for crude growth rate.

Answer:

E. subtracting the crude death rate from the crude birth rate