Question

How long did it take for the population to double a third time? A fourth time?

Answer 1

To calculate multiple doublings, one can use exponential growth. Doubling a town's population from 800 to 1600 would take 10 years, reaching the year 1940, and another doubling to 3200 would occur by 1950. Over time, the doubling time can change based on population growth rates.

Step-by-step explanation:

To determine how long it takes for a population to double multiple times, we can apply the concept of exponential growth. Based on the information given, various doubling times can be observed, such as a town's population doubling every 10 years. Starting at 100 people in 1900 and doubling every 10 years, by using the rule of 70 (which suggests that at 7% annual growth, doubling happens every 10 years), we get an obvious pattern where the population would reach 200 people in 1910, 400 people in 1920, and so on.

By the third doubling, you would have 800 people in 1930. To get the population to double for a third time to 1600, we add another 10 years to the timeline, making it the year 1940. For a fourth doubling to 3200, we add another 10 years, which brings us to 1950. If we continue this, we find that the population indeed approaches 7 billion (which would be the 26th doubling) in approximately 260 years, around the year 2160.

However, the doubling time can change over time based on actual growth rates. For instance, between 1965 and 1980, the world population grew at an annual rate of 2%, suggesting a doubling time of 36 years. This shows that doubling times can vary based on the annual growth rate of the population.

Answer 2

Based on the data in the image (Statistics on Human Population), it took approximately:

100 years for the population to double a third time.

100 years for the population to double a fourth time.

Here's how I arrived at this answer:

Identify relevant data points: We can see from the table that the population doubled from 0.5 billion to 1.0 billion between 1650 and 1750 (100 years).

Assume constant doubling rate: Since the population doubled within 100 years, we can assume a constant doubling rate for the sake of estimation.

Apply doubling rate: Assuming the population continues to double at the same rate, it would take another 100 years to reach 2.0 billion (double of 1.0 billion) and another 100 years to reach 4.0 billion (double of 2.0 billion).

Note:

This is an estimation based on limited data points and assumes a constant doubling rate, which may not be entirely accurate due to various factors influencing population growth.

The image only shows data until 2004, so we cannot confirm this doubling pattern beyond that year.

Complete the image: