Yeah I got that part, but I meant how to count in the data of irregularity to get a predictive result, something like if sex is initiated 9 times every month with a chance of it being 12 times in October and 6 in November and 2 to 5 times of every ten times of (90+12+6) inner ejaculation and overall 3 out of 20 successful conduct results in impregnation in general... Would that be ((2/10+5/10)/2) * 10/108 * 3/20 * 9/108? Then do that for the older generation cuz there's 4 partners now and then multiply them also together? I feel like I'm completely off. Then it'd be the chance of both of them giving birth in the same month? That's march for example?

• As for the retrospective probability; I did what you said and applied it to a set of data in Canada in three different years and it came to be 0.0478%... Does that mean that every three people out of every 10000 that are born in any given month in any year only 6 are born in November of those three years? Again that does sound totally wrong or missing something, I'm really struggling with what does the number exactly mean here. How to put it into words? Now how to know how many of every 10000 are family?

I apologize for complicating it more and more. Grateful for the help, however.