MATHEMATICAL APPROACH TO POPULATION STUDIES. Population studies usually is associated with lots of calculations and it is very important students to understand and get used to various formulae for solving specific problems associated with population.
Some population formulae
- Formula 1
Population density = Total population
Land area
- Formula 2
Total population = No. of males + No of all females
- Formula 3
Total population = Population density x Land area
- Formula 4
Land area = Total population
Population density
Example of mathematical approach to population studies
The total number of males in a country which has a total land area of 140,000 square kilometers is 150,000,000, while that of the females is 130,000,000 including all migrants calculate:
- The total population of the country
- The population density of the country
Solution
- Total population
= No of all males + No of all females
= 150,000,000 + 130,000,000
= 280,000,000 people
- Population density = Total population
Land area
280,000,000
= 140,000
= 2000 persons / sq km
Alternatively, (a) can be solved by
Total population
= population density x land area
= 2000 x 140,000
= 280,000,000 people
Example 2 of mathematical approach to population studies
If the population density if tanko district is 3,500 persons per square kilometer and the total population is 1,400,000 people. Calculate the total land area of tanko district.
Solution
Land area = Total population
= population density
= 1,400,000 people\
3,500 persons /km2
= 400 square kilometers
Formula 5
Rate of population growth R,
= Birth rate – Death + Net migration
Formula 6 of mathematical approach to population studies
Net migration = Immigrants – emigrants
I.e. Net migration is the difference between the number of immigrants and emigrants
Formula 7 of mathematical approach to population studies
Natural increase = birth rate – death rate
Formula 8 of mathematical approach to population studies
Percentage increase
= New population – old population
Old population x 100
Formula 9
Dependency ratio
= Dependent population
Working or Independent population
Note: Dependency ratio may be defined as the ratio o
f dependent population to independent population i.e. DR = DP:IP
Example 3 of mathematical approach to population studies
Use the information table in 11.1 and answer the following questions
Table 11.1: Population statistics of a country in 1980 and 1996
| Year | 1980 | 1996 |
| No of births in million No of deaths in million No of immigrants in million No of emigrants in million Total population in million | 56 | 48 12 10 4 98 |
Calculate following using mathematical approach to population studies
- The natural increase of the population in 1966
- Determine the net migration within the period
- The rate of growth of the population in 1966
- Calculate the population of the country in 1966
- What is the percentage increase in the population of the country from 1980 to 1966
Solution
- Natural Increase
= Birth rate – Death rate
= 48 million – 12 million
= 36 million
- Net migration = Immigrants – Emirates
= 10 million – 4 million
= 6 million
- Rate of population growth R, = Birth rate – Death rate + Net migration
No of Birth = 48 million
No of death = 12 million
Net migration = (immigrants – emigrants)
R = (48 – 12) + (10 – 4)
= 36 + 6 = 42 million
- Population of the country in 1996
= 1980 population + Net migration
+ (Number of births – Number of deaths)
= 56 million + 6 million
+ (48 million – 12 million)
= 62 million + 36 million
= 98 million
- Percentage increase from 1980 to 1996
= New population – Old population x 100
Old population
= 98 million – 56 million x 100
56 million
= 42 million x 100
56 million
= 75%
Example 4
The data in table 11.2 show a hypothetical age distribution of the population of a town in Nigeria.
Table. 11.2 shows a hypothetical age distribution of the population of a town in Nigeria
| Sex | Age in years 10 and below | 11 – 14 | 15 – 35 | 36 – 64 | 65 and above |
| Male | 1350 | 2275 | 1135 | Y | 3250 |
| Female | 2650 | 2725 | 1365 | 4265 | Z |
| Total | 4000 | X | 2500 | 7500 | 6000 |
From this data, calculate:
- X, Y, Z.
- The total population of the town.
- The difference between the population of male and female aged 14 and below
- The percentage of the population aged 14 years and below.
- The dependency ratio in the town (SSCE June 1997).
Solution
1(a) X = Male (2275) + Female (2725) = 5000
Y = Total – Female = 7500 – 4265 = 3235
Z = Total – Male = 6000 – 3250 = 2750
(b) Total population
10 and below = 4, 000
11 – 14 = 5, 000
15 – 35 = 2, 500
36 – 64 = 7, 500
65 and above = 6, 000
Total = 25, 000
Total population of the town is 25, 000 people.
- Female 14 years and below
= 2650 + 2725 = 5375
Male of 14 years and below
= 1350 + 2275 = 3625
/ Difference between the populations of male and female aged 14 and below:
= 5375 – 3625 = 1750
- Percentage of population aged 14 years and below:
Female aged 14 years and below + male aged 14 years and below:
= 5375 + 3625 + 9000
Or
4000 + 500 = 9000
= 9,000 x 100
25,000 1
= 36%
- Dependency ratio
= population of less than 14 years +
population of more than 65 years
Population of 15 – 35 + population of 36 – 64 years
Dependency ratio = 9000 + 6000
2500 + 7500
= 15,000 = 3
10,000 2
= 3: 2
Formula 10
Population figures can be represented in form for table (as in table 11.1 and table 11.2) and in bar and pie charts (see chapter 2 units 2.4 and 2.5).
Example 5
The pie chart in fig 11.3 represents the age distribution of population is 240 million.
age distribution of population
From the information in the diagram calculate the:
- Population of children between 0 and 17 years
- Population of old people (60 + years)
- Working population 18 – 59 years
- Calculate the dependency ratio.
Solution
- Population of children between 0 and 17 years
= 120 x 240 = 80 million
360 1
- Population of old people (60 + years)
= 90 x 240 = 60 million
360 1
- Working population 18 – 59 years
= 150 x 240 = 100 million
360 x 1
- Calculate the dependency ratio.
Population of children (0 – 17 years ) +
= population of old people (65 years)
Working population of (18 – 64 years)
= 80,000,000 + 60,000,000
100,000,000
Dependency ratio = 140,000,000
100,000,000
= 1.4
1
= 1.4:1
= 7:5
Example 6
The pie chart below shows the age distribution of population in thousand of an island for the year 2000. The total population of the island is 245,000.
Use the information supplied to answer the question that follows. (Show all workings clearly).
- Calculate the number of person in the different age groups.
- What is the dependency ratio of the population?
- Give three implications of the above population structure.
Solution
Age group 0-16 years = 149,722.20
220 x 245,000
360 1
Age group 17-45 years = 51,041.70
75 x 245,000
360 1
Age group 46-60 years = 29, 263, 90
43x 245,000
360 1
Age group 60+ years = 14, 972.20
22 x 245,000
360 1
- Dependency ratio
= 145,722.20 +14,972.20
51,041.70 + 29,263.90
= 164,694.40
80,305.60
= 2:1 (2 to 1)
Or
(2:1 to 1)
Implications of population structure
Increased demand for goods and service required by the youth and old ones because they form the large percentage of the population.
Implications of population structure
Increased demand for goods and service required by the youth and old ones because they form the large percentage of the population.
Implications of population structure
Increased demand for goods and service required by the youth and old ones because they form the large percentage of the population.
Implications of population structure
Increased demand for goods and service required by the youth and old ones because they form the large percentage of the population.
- If the items required by the young and old ones re not produced locally, there will be increased importation and resultant stain on the balance of payment.
- Low level of savings and investment because of the high dependency ratio.
- Increased taxation and borrowing by government to meet increased demand for consumable items because the taxable population is small.
- High prospective labour force because of the large proportion of young ones.
- The current labour is low.
Example 7
The table shows the natural growth rate of the population of country N over a period of time. Use the information contained in the table to answer the following questions.
- Determine L P QS and T
- With the use of a bar chart graphically present the changes in the natural growth rate over the year. (use of graph sheet is essential)
- Outline any three reasons for changes in birth rate.
Solution
- Early or late marriages. Early marriages increase birth rates while late marriages reduce it.
- The higher the number of females in a population the higher the birth rate and vice versa.
- Population control methods and campaigns can also reduce birth rates.
- Improved medical facilities increase birth rates
- Changes in traditional attitudes and beliefs of people to have large facilities can reduce birth rates.
- Improved economic situations can affect birth rates particularly in developing societies
- economic tools for nation building
- factors affecting the expansion of industries
- bud
- mineral resources and the mining industries
- demand and supply
- types of demand curve and used
- advertising industry
- factors of production
- entrepreneur
- joint stock company
- RINDER PESTS
148. NEWCASTLE DISEASE
149. BACTERIA DISEASES
150. ANTHRAX
151. BRUCELLOSIS
152. TUBERCULOSIS
153. FUNGAL DISEASES
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