Expected girls from one couple$ {}=0.5\cdot1 + 0.25\cdot1 =0.75$ Expected boys from one couple$ {}=0.25\cdot1 + 0.25\cdot2 =0.75$ 1 As I said this works for any reasonable rule that could exist in the real world. An unreasonable rule would be one in which the expected children per couple was infinite.
Expected number of ratio of girls vs boys birth - Cross Validated
Considering the population of girls with tastes disorders, I do a binomial test with number of success k = 7, number of trials n = 8, and probability of success p = 0.5, to test my null hypothesis H0 = "my cake tastes good for no more than 50% of the population of girls with taste disorders". In python I can run binomtest(7, 8, 0.5, alternative="greater") which gives the following result ...
Probability of having 2 girls and probability of having at least one girl Ask Question Asked 8 years, 8 months ago Modified 8 years, 8 months ago
Probability of having 2 girls and probability of having at least one girl
A couple decides to keep having children until they have the same number of boys and girls, and then stop. Assume they never have twins, that the "trials" are independent with probability 1/2 of a boy, and that they are fertile enough to keep producing children indefinitely.
The net effect is that even if I don't know which one is definitely a boy, the other child can only be a girl or a boy and that is always and only a 1/2 probability (ignoring any biological weighting that girls may represent 51% of births or whatever the reality is).
Use standard type for Greek letters, subscripts and superscripts that function as identifiers (i.e., are not variables, as in the subscript “girls” in the example that follows), and abbreviations that are not variables (e.g., log, GLM, WLS). Use bold type for symbols for vectors and matrices. Use italic type for all other statistical symbols.
If the probability for a girl is determined by the fact that there are 2 boys and 2 girls in this family of 4 children. Then the probability for the 3rd child to be a girl, given the first 2 are boys, is 100%.