Question

Suppose the waiting time for the next earthquake in a certain region is exponentially distributed with parameter lambda=0.125. Find the average time until the next earthquake in that region.

Answer 1

isnt this a poisson distribution? if so, what is the function of poisson

Answer 2

\[P(X=x) = \frac{ (\lambda t)^xe^(-\lambda t) }{ x}\]
I don't understand what it is asking, I thought lambda was the mean?

Answer 3

lambda should be the mean and ... what is it, variance or standard deviation.