In a newspaper, it was reported that the number of yearly robberies in Springfield in 2013 was 180, and then went down by 40% in 2014. How many robljeries were there
in Springfield in 2014?

The number of robberies in 2014 is 108

Step-by-step explanation:

Here, we want to calculate the number of robberies in 2014

from the question, the robberies went down by 40%

Let the number of robberies in 2014 be x

Thus;

40/100 * 180

= 72

This means that the value it went down was by 72

Thus;

x = 180-72

x = 108

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! )