Answer: the number of years is 7.3 years
Explanation:
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^ t
Where
A represents the population after t years.
t represents the number of years.
P represents the initial population.
r represents rate of growth.
From the information given,
P = 1250
A = 1000
r = 3% = 3/100 = 0.03,
Therefore
1000 = 1250(1 - 0.03)^t
1000/1250 = (0.97)^t
0.8 = 0.97^t
Taking log of both sides, it becomes
Log 0.8 = tLog 0.97
- 0.0969 = - 0.0132t
t = - 0.0969/- 0.0132t
t = 7.3 years