Question

The bird population on an island is declining at a rate of 2.2% per year. If the population was 3500 in the year 2009, which is the best prediction of the population in the year 2014? 3500 in 2009

3500 (.022) = 77
3500 - 77 = 3423
3423 in 2010
3423 (.022) = 75.31
3423 - 75.31 = 3347.69
3347.69 in 2011
3347.69 (.022) = 73.65
3347.69 - 73.65 = 3274.04
3274.04 in 2012
3274.04 (.022) = 72.03
3274.04 - 72.03 = 3202.01
3202.01 in 2013
3202.01 (.022) = 70.44
3202.01 - 70.44 = 3131.57
3131.57 in 2014

Answer 1

The answer to this is 3132 for 2014, and 3063 for 2016

Answer 2

Given:
2009 : 3,500 population
decrease of 2.2% per year.
100% - 2.2% = 97.8%

2014 - 2009 = 5 years

3,500 * (0.978)^5 = 3,500 * 0.89473 = 3131.57

The bird population in 2014 will be 3,131.57 or 3,132.