Page 27 - Health, Population and Environment Education 10

Worked out example: 11
The population of a city was 225000 in the beginning of year and at the end of year, it
reached 2,20, 000. About 1200 people in migrated and 900 people migrated out from the
city. Now, calculate net migration rate of that city.

Solution:
Given,

In a city,
Population at the beginning of year = 225000
Population at the end of year = 220000
Number of in-migrants = 1200

Number of out-migrants = 900
Net Migration Rate (NMR) = ?
We know,

Mid year population of that city in a year
Population at the beginning of year + Population at the end of year
=
225000 + 220000 2
=
2
445000
=
2
= 222500
Again,
Number of in-migrants – Number of out-migrants
NMR = × 1000
Mid year population of a place in a year

1200 – 900
= × 1000
222500
= 1. 34

∴ NMR of that city was 1.34 per 1000.
In the above example, NMR is calculated as 1.34 per 1000. It means that nearly 1 in-migrant
is more than out migrant among 1000 mid year population in a city.

GREEN Health, Population and Environment Education Book-10 27