The formula for **exponential growth** is

y = a(1+r)^{t}

where *a* is the initial amount, *r* is the rate of increase expressed as a decimal, *t* is the time elapsed, and *y* is the final amount.

Plug in 33,000 mega liters for the initial amount, 0.1 for the rate of increase, and 18 years for the time elapsed.

*y* = *a*(1 + *r*)*t*

*y* = 33,000(1 + 0.1)18

*y* = 33,000(1.1)

*y* ≈ 33,000(5.5599173)

*y* ≈ 183,477.2709

Round to the nearest hundredth.

183,477.2709 → 183,477.27

To the nearest hundredth, Stafford will use 183,477.27 mega liters of water annually.

Skills to further recall:

What is exponential growth and exponential decay

https://courses.lumenlearning.com/waymakercollegealgebra/chapter/exponential-growth-and-decay/

What is an exponential function

How to calculate a value to the nearest hundredth