how do you know that this is a poisson distribution even if the average is not given.

Question

trancenova · Answer

Hmm would you be able to tell me what you are given?

Usually the poisson distribution only has the one parameter - the mean - which controls how "spread out" the distribution is. One thing easy to tell about the poisson distribution is that it is discreet, that is they are whole numbers ALSO the poisson distribution doesn't go below zero. This is because it deals with count information, things you can count don't go negative :)

You can tell it apart from the Binomial distribution as the binomial has an amount that the numbers are "out of" so it has an upper and lower limit whereas theoretically the poisson distribution can keep going.