Published online by Cambridge University Press: 31 July 2008
Distributions of reported coital rates are positively skewed. The means of such distributions seem to be roughly proportional, not to their variances, but to their standard deviations.
The coefficient of variation of distributions of reported coital rates—at least for relatively homogeneous samples—is of the order of 2/3. It is estimated that the coefficient of variation of the distribution of true (as opposed to reported) values would be about ½ at the time of first conception.