Solving a Population Growth Problem: Finding the Annual Death Rate

[heavyarms]

help please: sequence problem

how do you solve this question please help! thx!

A current population is 2 000 000 and it increases 7% annualy. However each year a certain number of people die (this amount is constant for every year). How many people die each year if the population is to become 2 500 000 in 8 years?

please list steps thx!

 

[futb0l]

let a = 2 000 000 (the starting number)
r = 1.07 (the percentage, 100% + 7%)
n = 8 (because - you want to find out after 8 years)

using the Geometric Sequence formula...

$$t_n = ar^{n-1}$$

SHould be pretty simple.

 

[BobG]

Almost. After you calculate the growth with no deaths (futbol's post), subtract 2,500,000. That tells you how many died over the 8 year period. It's a constant rate, so you need the average number of deaths per year.