If the population of a certain town decreases by 4.5% each year, we form a geometric sequence with first term equal to 8,500 and r equal to 0.955.
(a) The equation is then,
An = (8,500)(0.955)^n
Where n is the number of years.
(b) Substituting 7000 to An and solving for n,
7000 = 8500*(0.955)^n
The value of n from the equation is 4.2 years.