Statistics and Data Analysis for Microarrays Using R and Bioconductor, 2nd Edition

242 Statistics and Data Analysis for Microarrays Using R and Bioconductor

Let us cons ider the following example. We are trying to estimate probability

of occurrence of an albino pigeon in a given a rea. This probability can be

estimated by catching a number of pigeons in the area. Most of the pigeons

will b e gray but a few will also be white (albino). If 100 birds are caught of

which 25 birds ar e white, the empir ic al probability of an albino pigeon in the

area is 0.25 or 25%.

8

The classical probability of an event A is defined a s:

P (A) =

n(A)

n(S)

(8.45)

where S is the entire sample space. The definition simply s ays that the classical

probability