Question

1. In 1990, the rate of change of the world population was approximately 0.09125 billion per year (or approximately 1 million people every four days). The world population was estimated to be 5.3 billion in 1990.According to the model, when will the population of the world be double the 1990 population?

a. The population will double in approximately 270 years time, by 2260.
b. The population will double in approximately 17 years time, by 2007.
c. The population will double in approximately 58 years time, by 2048.
d. The population will double in approximately 116 years.

2. In 1990, the rate of change of the world population was approximately 0.09125 billion per year (or approximately 1 million people every four days). The world population was estimated to be 5.3 billion in 1990.

Use the linear model to predict the world population in 2025.

a. According to the model, in 2025 the world population will be 84,937,500,000
b. According to the model, in 2025 the world population will be 8,493,750,000
c. According to the model, in 2025 the world population will be 5,302,607,000
d. According to the model, in 2025 the world population will be 8,037,500,000

Answer 1

The rate of change was 0.09125 billion people every year.
For the population to double, the additional 5.3 billion people was added to the population of 1990
0.09125 billion people in 1 year.
5.3 million people in (5.3 / 0.09125) = 58.1 years.

Therefore, the population will double in approximately 58 years time, by 2048.

2.) 2025 is 35 years after 1990.
0.09125 billion people in 1 year
0.09125 * 35 = 3.19375 billion people in 35 years.

Therefore, according to the model, in 2025 the world population will be 5.3 billion + 3.19375 billion = 8,493,750,000