Tuesday Population calculations

​Population calculations

By Jason Gvazdauskas

© 2014 Pearson Education, Inc.

Populations may grow, shrink, or remain stable

▪ Natural rate of population increase=

(Crude birth rate) − (crude death rate)

▪ Population change due to internal factors

▪ Population growth rate=

(Crude birth rate + immigration rate) − (Crude death rate + emigration rate)

▪ Net changes in a population’s size/1000/year

▪ Growth rate as a percent = Population growth rate × 100%

▪ Populations of different sizes can be compared

Crude Birth Rate

• Number of births per 1,000 people in a population in a year.

• The world's population is 8.2 Billion people

• The CBR for the world is 17

• So, through the math, the world is adding 139,400,000 people

• (8,200,000 * 17)

• Formula =(Number of live births / Estimated midyear Population) x 1,000. 

  
  

Crude Death Rate

• The number of deaths in a population per 1000 people in a year.

• Again, the world's population is 8.2

• The CDR is 7.7

• So effectively the world is losing 63,140,000 people per year.

• Formula =(Number of live deaths / Estimated midyear Population) x 1,000. 

Multiple Choice

The CBR of Togo is 30 and the CDR is 10. What is the growth rate?

(Crude birth rate - Crude death rate)/10 = r%

• 20%

• 40%

• 2%

• 6%

Natural Increase Rate

• Crude Birth Rate - Crude Death Rate

• 18.1 - 7.7

• NIR for the world is +10.4 people per 1000 per year.

Multiple Choice

The CBR of Togo is 30 and the CDR is 10. What is the Natural increase?

• 20%

• 40%

• 2%

• 6%

​Population Growth

​Birthrate and Death rate

​

• Growth occurs when birthrate is higher than its death rate

• Equal birth and death rate - zero growth

• Death rate higher than birthrate- decrease in populaiton

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Some text here about the topic of discussion

Multiple Select

Factors that affect population size:

DECREASE: Number of ___________ & ____________

Choose all that applies.

• Birth

• Death

• Immigration

• Emigration

​Population Growth

​Immigration and Emigration

​

​

• Immigration: when individuals move into a population range

• ​Emigration: when individuals move out of a population range

  • ​

Some text here about the topic of discussion

Multiple Choice

A small island nation is tracking its total population.  It started with exactly 100 people. During the year, 10 people immigrated, while 20 emigrated.  The birth rate was 15, and the death rate was 5.  What is the new population of the country?

• 115

• 110

• 90

• No change; the population is still 100.

Multiple Choice

A metropolitan area of 100,000 people has 2,000 births, 500 deaths, 200 emigrants, and 100 immigrants. Calculate the population growth rate.

• 1.2 percent

• 1.4 percent

• 1.6 percent

• 1.8 percent

Population Density

Doubling Time

• The amount of time needed for a population to double based on it's natural increase rate.

• Rule of 70

• formula=70/growth rate as a percent​

Multiple Choice

In 2012, there were 20 births per 1,000 people and 5 deaths per 1,000 people in Peru. Calculate the approximate doubling time of Peru's populaiton.

• 5 years

• 15 years

• 47 years

• 72 years

Multiple Choice

The town of Fremont has a population of 2,000. In 2019, the town has 50 deaths, 20 immigrants, and 30 emigrants. The town's population growth rate is 4.5%. Calculate the approximate doubling time of Fremont.

• 16 years

• 22 years

• 45 years

• 88 years

Multiple Choice

A country has a net immigration rate of 3 per 1,000, a CBR of 9 per 1,000, and a CDR of 11 per 1,000. Calculate the growth rate of this country.

• 0.1 percent

• 0.2 percent

• 0.5 percent

• 1 percent

Multiple Choice

The town of Fremont has a population of 2,000. In 2019, the town has 50 deaths, 20 immigrants, and 30 emigrants. The town's population growth rate is 4.5%. Calculate the crude birth rate in 2019.

• 70

• 75

• 95

• 105