Suppose you are provided the following data by census department of Peshawar city for following years: Year 1970 1980 1990 2000 2010 Population 650,000 780,000 950,000 1,200,000 225,000 Being a demographer you were asked to forecast the population for year 1940. How will you ascertain that the population is growing Arithmetically or Geometrically or in other words it is an arithmetic or Geometric growth. Discuss the method you used and answer the question with full justification.

 

Suppose you are provided the following data by census department of Peshawar city for following years:

Year                        1970                  1980                        1990                     2000                     2010

Population      650,000              780,000              950,000              1,200,000          225,000

Being a demographer you were asked to forecast the population for year 1940. How will you ascertain that the population is growing Arithmetically or Geometrically or in other words it is an arithmetic or Geometric growth. Discuss the method you used and answer the question with full justification.    

Answer:

 

                I will suggest geometric growth method for population forecasting, because the population growth data is increase constantly. It is not showing us the fast growth. The population is growing Geometrically from decade to decade is remain constant.

From 1970-1980

ΔP = 780,000 – 650,000  = 130,000

From 1980-1990

ΔP = 950,000 – 780,000 = 170,000

From 1990-2000

ΔP = 1,200,000 – 950,000 = 250,000

From 2000-2010

ΔP = 225,000 – 1,200,000   = -975,00

From the rate of change it can be observed that, the population is not increasing linearly, so that’s why the population is growing geometrically.