Question

Consider the following data.

Rates for Cheetah Population from 2011 to 2012
Cause of change
2011
2012
Deaths
2
1
Births
5
4
Immigration
6
1
Emigration
8
3

Which would have to happen to keep the population growth of cheetahs in 2013 the same the previous years?
4 deaths, 7 births, 2 immigration, 6 emigration
3 deaths, 6 births, 5 immigration, 7 emigration
5 deaths, 2 births, 8 immigration, 3 emigration
1 deaths, 5 births, 3 immigration, 7 emigration

Answer 1

Net change = births + immigration − deaths − emigration.

2011: 5+6−2−8 = +1
2012: 4+1−1−3 = +1

So 2013 must also have net +1. Check option B:
6+5−3−7 = 11−10 = +1.

Answer: 3 deaths, 6 births, 5 immigration, 7 emigration.