Answer:
No question is asked, but a potential answer is outlined below.
Explanation:
There is no question, just 2 statements.
Lets assume the question to be "What is a formula for calculating the population of Chicago for year x, where x is years since the current year (year 0). Assume the growth rate of -11% remains the same every year.
Population(x) = (2,500,00)*(1-0.11)^x
The term (1+0.11)^x is simply the factor 1.11 which represents the growth rate per year. It is raised to the xth power for the year year x (after the current year)
The base population is 2,500,000 in year 0:
Population(0) = (2,500,000)*(1-0.11)^0 [anything raised to the zero power is equal to 1]
Population(0) = (2,500,000)*(1)
Population(0) = 2,500,000
The base population is 2,500,000 in year 4:
Population(4) = (2,500,000)*(1-0.11)^4
Population(0) = (2,500,000)*(0.627)
Population(0) = 1,568,556 after 4 years of 11% decline
Out of curiosity, we might ask how many years before Chicago's population reaches 1?
Population(x) = (2,500,00)*(1-0.11)^x
1 = (2,500,00)*(1-0.11)^x
x = 126.4 years