A population numbers 13,000 organisms initially and decreases by 2.7% each year. Suppose
P
represents population, and
t
the number of years of growth.

An exponential model for the population can be written in the form
P=ab^t

the answer is d. 75%

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for