Doubling Time = THE RULE OF 70(70%) or (0.7)
r (in percent form) r (in decimal form)
Finding Future Population from Growth Rate…
(initial population) x (growth rate) years = Final Population
NOTE: a growth rate of 3% is expressed as 1.03; a growth rate of 0.25% is 1.0025
for example: (468,843 people ) X ( 1.03 )10 years = 630,085 people
All answers are approximate – when you aren’t using a calculator you have a little liberty to round!
At the end of 2002, there were 1,284.53 million people living in China. China is the third largest country in the world with an area of 9.6 million square kilometers. What is the population density of China?
Population Density = (Population) = 1284.53 = 134 people per sq km
China has 130.04 million hectares of land under cultivation. What is the average amount of cultivated land in sq km that supports each person (100 hectares =1 sq km = 247 acres)?
At the end of 2002, there were 502 million urban residents. What percentage of the total population were living in cities?
Percentage = Amount of interest x 100 = 502 = 39%
Total Amount 1284
At the end of 2002, there were 661.15 million males in China. What percent of the total population were males?
661 x 100 = 51% males
22.4% of China’s total population was in the age group of zero to age fourteen. How many children is that? If the average number of students in each elementary school is 500, how many elementary schools are needed in China (assume that all children between the ages of 0 and 14 attend)?
Oddly, while China has relatively few cars on the highways compared to the size of its population, they have the highest number of traffic fatalities in the world: more than 100,000 per year. What is the per capita death rate in China for car fatalities?
Per capita means per person. 100,000 = 0.0000779 accidents per person