## Kagome_gurl8 2 years ago Need serious help on this one. An initial population of 655 quail increases at an annual rate of 18%. Write an exponential function to model the quail population.

1. ZeHanz

General formula for this is $P(t)=b⋅g^t$where P is the population at time t, b is the population at the beginning (t=0) and g is the growing factor. I'd say b = 655. Do you know how to get from 18% increase per year to the growing factor per year?

2. campbell_st

why not just use the compound interest formula A = P(1 + r/100)^t $A = 665(1 + \frac{18}{100})^t$

3. ZeHanz

Well that is just the same as realising that 18% increase means you now have 110%+18%=118%. So the amount is multiplied with 1.18, making the formula:$P(t)=655 \cdot 1.18^t$ In the end, it's all the same...