E1C04 09/14/2010
14:7:40 Page 124
Poisson
Events randomly occurring in
time;
p(x) refers to probability of
observing
x events in time
t; here
l refers to
x
0
p x
ð Þ ¼
e
Àl
l
x
x!
p(x)
Binomial
Situations describing the number
of occurrences,
n, of a particular
outcome during
N independent
tests where the probability of any
outcome,
P, is the same
p n
ð Þ ¼
N!
N À n
ð
Þ!n!
!
P
n
1
À P
ð
Þ
NÀn
p(n)
Table 4.2
(Continued)
124