Answer:
It will take the 20 years for the population to quadruple.
Step-by-step explanation:
Exponential population growth:
An exponential model for population growth has the following model:

In which P(0) is the initial population and r is the growth rate, as a decimal.
It grows with a doubling time of 10 years.
This means that
. We use this to find r. So



![\sqrt[10]{(1+r)^10} = \sqrt[10]{2}](https://tex.z-dn.net/?f=%5Csqrt%5B10%5D%7B%281%2Br%29%5E10%7D%20%3D%20%5Csqrt%5B10%5D%7B2%7D)


So


Determine how long it will take for the population to quadruple.
This is t for which P(t) = 4P(0). So







It will take the 20 years for the population to quadruple.
The number 1000 less than 921,438 is 920,438. What you do is take 921,438 and subtract 1000 from it.
The plus sign means that we have to sum all the terms inside of the second parenthesis, while the minus sign means that we have to change all the signs inside the last parenthesis:

Now we only have to gather all like terms:

Answer:
The equation is Linear
Step-by-step explanation: