Standard Error Of 'p', The Recombination Faction

Fisher showed that the variance of the maximum likelihood estimate of P is:

Where Vr is the variance of p. Vp is the s.e.(p) squared. We take the second derivative of the maximum likelihood equation, after substituting a for mn. The result for the testcross is:

Variance(p) = Vp = p(1-p) which is the formula
                             n

for the variance of ratio.

Example