Question

A town hasapopulation of p people based on a 2010 census. According to research conducted by the town council, the population of the city is expected to increase by 5 percent per year. According to the estimate, the expected population of the town in 2020 is 810. To the nearest whole number, what is the value of p ?

Answer 1

Answer:

p = 497 ( to the nearest whole number)

Step-by-step explanation:

In order to do this calculation, we will apply the principle of accounting, where a certain amount is compounded periodically and yielding a future value. Compound interest is used because the percentage growth rate is added on the new amount gotten each year, and not on the first or original amount.

Hence:

FV = PV × $(1+ \frac{r}{n}) ^{n*t}$

where FV = future value = population in 2020 = 810

PV = present value = population in 2010 = p

r = percentage growth rate in decimal = 5% = 5/100 = 0.05

n = growth rate period per year = once = 1

t = time in years = 2010 to 2020 = 10 years

∴ $810 = p * (1+ \frac{0.05}{1}) ^{1*10}$

$810 = p * (1.05) ^{10}\\810= p(1.6289)$ (dividing both sides by 1.6289)

p = 810 ÷ 1.6289 = 497.2 = 497 (to the nearest whole number)

∴ population in 2010 = 497