Year 1940 1950 1960 1970 1980
Rate of change (million people per year) 29 49 67 76 98
If the population in 1940 were 2158 million and if the population in 1980 were 4846 million, what would be the true total change in population?
To find the true total change in population, we need to calculate the cumulative sum of the rates of change for each decade.
Step 1: Calculate the population change for each decade.
In 1950, the population change = (Rate of change in 1940-1950) * (Number of years) = 49 million * 10 years = 490 million.
In 1960, the population change = (Rate of change in 1950-1960) * (Number of years) = 67 million * 10 years = 670 million.
In 1970, the population change = (Rate of change in 1960-1970) * (Number of years) = 76 million * 10 years = 760 million.
In 1980, the population change = (Rate of change in 1970-1980) * (Number of years) = 98 million * 10 years = 980 million.
Step 2: Calculate the cumulative sum of the population changes.
Cumulative sum = 490 million + 670 million + 760 million + 980 million = 2900 million.
Step 3: Calculate the true total change in population.
True total change = Final population - Initial population = 4846 million - 2158 million = 2688 million.
Therefore, the true total change in population is 2688 million.
To find the true total change in population, we need to calculate the sum of the rate of change in population for each year.
The rate of change is given for each year:
1940: 29 million people per year
1950: 49 million people per year
1960: 67 million people per year
1970: 76 million people per year
1980: 98 million people per year
We can calculate the change in population for each decade by multiplying the rate of change by the number of years in each decade.
For the 1940s:
Change in population = 29 million people per year * 10 years = 290 million people
For the 1950s:
Change in population = 49 million people per year * 10 years = 490 million people
For the 1960s:
Change in population = 67 million people per year * 10 years = 670 million people
For the 1970s:
Change in population = 76 million people per year * 10 years = 760 million people
For the 1980s:
Change in population = 98 million people per year * 10 years = 980 million people
Finally, we add up the change in population for each decade to find the true total change in population:
True total change in population = 290 million + 490 million + 670 million + 760 million + 980 million = 3,190 million people
Therefore, the true total change in population from 1940 to 1980 would be 3,190 million people.