Question 328768
X=number of car passing in an interval of time

X~Poisson (mean=80/hour) or Poisson (mean 80/60min=4/3min)

{{{P(X=x)= mean^(x)*e^(-mean)/x! }}}   where x>=0)
{{{P(X=x)= (4/3)^x *e^(-4/3)/x!}}}



P(at least one car)= 1- P(no cars passing in the interval of interest)
P(X>=1)= 1-P(X=0) = {{{1 - e^(-4/3)}}} = 1-0.264=0.736