We have the following data:
Birth rate (b) = 5
Death rate (d) = 4
Imigration rate (i) = 8
Emigration rate (e) = 6
The formula for population growth (r) is:
r = (b+i) - (d+e)
So we have the following:
r = (5+8) - (4+6)
r = 13 - 10
r = 3
The population growth is then measured in 3.