Damn, forgiveness is easier than permission I suppose.
Scratch one of the “Yes” then. I answered for my parents.
I have no children, but I voted on behalf of my brother who has two daughters. 
I think (based on what I’m learning in Stats) that one should have an N of 100 to have a nice good sample size but I have no idea if that’s really true or not, and I’m doubting it.
Also, I think you should also have a 2:1 ratio in this test of yours.
The 4 TRUE options should have been:
MM/MF/FM/FF (and thus getting 2:1:1 as your possible answers). It would only be 50% if you compared it as “Same Sex” vs. “Not-same sex” with each having a 50% ratio, at least that’s the case if we were doing punnet squares and vastly simplifying the inheritance rations and such to 50% with 2 variables of the ration (XX*XY).
I doubt it’s that easy and realistic in the real world.
But hey, that’s a nice AP Bio question right there if you simplified it down that way!
Meh. I think you’re thinking of 30, at least for a t-distribution.
Of course. But if you look at the thread linked in post 3, there are those out there who believe the answer should be 50/50. I thought this poll might convince doubters that, even if they don’t believe it’s 1:2, at least it’s not 1:1.
Rejecting a null hypothesis that it is 1:1 is easy, using the t-distribution. With the present breakout of 14:27, we get 65.9% that the other child is a son, and a standard error with 41 observations of 7.4%. So even right now we can say with 95% confidence that the real breakout in the full population is somewhere between 51% and 81%.
In other words, it ain’t 50/50.
This does assume that the people who answered the poll have no expected bias from the population at large that has two kids, one of whom is a daughter.
fair enough.
I have only two children, both girls, but I’ve been pregnant four times in my life if that matters.
I’ve got two little girls, I’m surrounded by estrogen.
Oh yeah … to further muddy the waters … my boy and girl, the fraternal twins … they have a half sister and half brother too.
Two children: one boy, one girl.
Updating the stats - having the other child a boy is now at 63.4%, with a standard error of 5.7%.
One of each for me.
Two girls.
It’s good to see that this poll matches my math!
Both my son and my daughter love counterintuitive things.
I have two children, both daughters.
And I love them with all my being.
Two children, both daughters.
Nice results!