Apopulation of 800 cheetahs decreases by 13% per year. how many cheetahs will there be in the population after 5 years? round your answer to the nearest whole number. a. 735 b. 399 c. 347 d. 1474

Using the exponential decay formula Y = A(1-r)^t

Where A is the starting value, r is the percent of change and t is the time.

Y = 800(1-0.13)^5

Y = 800(0.87)^5

Y = 800(0.49842)

Y = 398.74 = 399

The answer is B. 399

the answer   is 200

step-by-step explanation:

this is a problem about poisson probabilities.   i don't know if you've

already studied poisson distributions, or if you have a place to look

to read more about the subject.  

here's how you can see a poisson distribution coming.   when there are

a lot of events that may happen at any time (or any place), and when

you're counting how many of them happen at a particular time (or a

particular place), and each event is independent of the others, then

the result is a poisson distribution.   this is roughly true for the

chocolate chips; one chip being in a cookie has only a small effect on

the probability that another chip will be in the cookie.

once you know you have a poisson distribution, you know a lot.   there

is only one parameter to a poisson distribution, so if you know the

mean, you know everything.   the form of the distribution is

  probability of n chips = {[e^(-x)]*(x^n)} / (n! )