The population of Boomtown is currently 14000 and expected to grow by $2.6 \%$ over the next year. What will its population be by then?

The population of Dullsville, on the other hand, is currently 2000 and expected to decrease by $3.1 \%$ over the next year. What will its population be by then?
Question 18

Step 1 ：The population of Boomtown is currently 14000 and expected to grow by 2.6% over the next year. We can calculate the population growth by adding the percentage increase to the current population.

Step 2 ：Using the formula \(P = P_0(1 + r)^n\), where \(P\) is the final population, \(P_0\) is the initial population, \(r\) is the growth rate (expressed as a decimal), and \(n\) is the number of time periods, we find that the population of Boomtown will be \(14000(1 + 0.026)^1 = 14364\).

Step 3 ：The population of Dullsville is currently 2000 and expected to decrease by 3.1% over the next year. We can calculate the population decrease by subtracting the percentage decrease from the current population.

Step 4 ：Using the formula \(P = P_0(1 - r)^n\), where \(P\) is the final population, \(P_0\) is the initial population, \(r\) is the decrease rate (expressed as a decimal), and \(n\) is the number of time periods, we find that the population of Dullsville will be \(2000(1 - 0.031)^1 = 1938\).

Step 5 ：Final Answer: The population of Boomtown will be \(\boxed{14364}\) and the population of Dullsville will be \(\boxed{1938}\).