Chapter 4, Problem 1AL

To determine

The population doubling time if it is growing at the rate of $1.1$  percent per year.

Answer to Problem 1AL

Doubling time is the time required for doubling a quantity. For the world population approximately $64$ years require if the growth rate is $1.1$ per year.

Explanation of Solution

Doubling time is defined as the time period which is required for doubling a quantity. Population doubling time is the time which is required for doubling the present human population size.

The doubling time of a population can be calculated by the rule of $70$. According to this rule, $70$ is divided by the growth rate of the population. For example, if the growth rate of the world population is $1.1$ per year then by applying the rule of $70$, one can calculate the doubling time of the world population.

As,

$\begin{array}{c}\text{Doubling}\text{time}\text{=}\frac{\text{70}}{\text{1}\text{.1}}\\ \text{=}\text{63}\text{.636}\text{years}\end{array}$

So, approximately $64$ years is required for doubling the world population.