Question

A conservationist determines that a particular beach is eroding at a rate of 1.1% each year. When writing an explicit formula to represent the amount of beach remaining each year, which value should she use as the common ratio?

Answer 1

okay well if u lose 1.1% every year means you are left with a 'REMAINING' percentage of 98.9% which is 0.989

Answer 2

Answer: She should use 0.989 as the common ratio.

Explanation:

Given: A conservationist determines that a particular beach is eroding at a rate of 1.1% each year.

i.e. the rate of decay k= 1.1%=0.011

When writing an explicit formula to represent the amount of beach remaining each year, the common ratio 'r' for decay rate k is written as :

`r=(1-k)=(1-0.01)=0.989`

Hence, she should use 0.989 as the common ratio.