Suppose a city with population of 700,000 has been growing at a rate of 6​% per year. If this rate​ continues, find the population of this city in 22 years.

The population in 22 years will be approximately
. ​(Round to the nearest whole number as​ needed and use commas.)

1 answer

To find the population of the city in 22 years given an initial population of 700,000 and an annual growth rate of 6%, we can use the formula for exponential growth:

\[ P(t) = P_0 \times (1 + r)^t \]

where:

  • \(P(t)\) is the population after time \(t\),
  • \(P_0\) is the initial population,
  • \(r\) is the growth rate (as a decimal),
  • \(t\) is the number of years.

In this case:

  • \(P_0 = 700,000\),
  • \(r = 0.06\) (since 6% as a decimal is 0.06),
  • \(t = 22\).

Now we can plug the values into the formula:

\[ P(22) = 700,000 \times (1 + 0.06)^{22} \]

Calculating \(1 + 0.06\):

\[ 1 + 0.06 = 1.06 \]

Now calculate \( (1.06)^{22} \):

\[ (1.06)^{22} \approx 3.5836 \quad \text{(using a calculator)} \]

Now multiply this by the initial population:

\[ P(22) \approx 700,000 \times 3.5836 \approx 2,508,520 \]

Therefore, rounding to the nearest whole number, the population in 22 years will be approximately 2,508,520.

So the final answer is:

2,508,520.