Answer: it take 5.448 years for the population to reach one million.
Step-by-step explanation:
The population of a city is modeled by the equation
P(t) = 256,114e0.25t
where t is measured in years.
For the population to reach 1000000, it means that
1000000 = 256114e0.25t
1000000/256114 = e0.25t
3.9045 = e0.25t
Taking ln of both sides of the equation, it becomes
Ln 3.9045 = Ln e0.25t
1.362 = 0.25t
t = 1.362/0.25
t = 5.448 years