Binomial Distribution Part II

Example

Aa x aa, family size = 8
P (7 Aa and 1 aa) progeny

There are eight different orders that include seven Aa and one aa progeny in a family of eight progeny. The probability of each of these orders is (1/2) = 1/256.

P (Aa Aa Aa Aa Aa Aa Aa aa) = 1/256
P (Aa Aa Aa Aa Aa Aa aa Aa) = 1/256
P (Aa Aa Aa Aa Aa aa Aa Aa) = 1/256
P (Aa Aa Aa Aa aa Aa Aa Aa) = 1/256
P (Aa Aa Aa aa Aa Aa Aa Aa) = 1/256
P (Aa Aa aa Aa Aa Aa Aa Aa) = 1/256
P (Aa aa Aa Aa Aa Aa Aa Aa) = 1/256
P (aa Aa Aa Aa Aa Aa Aa Aa) = 1/256
P (aa A P (seven Aa, one aa) = 8/256

The coefficient of 8 is provided by the following formula:

Where n = total number in sample; r = number of 'successes'; n-r = number of 'failures'.
genotn=r+(n-r)