STATISTICS? MATH PEOPLE? ROO TO HEN PROBABILITY....???

[Rare Feathers Farm]

So let's say I have six babies. What the likely sex ratios? 50% of each? Last year, I hatched out two Sultans, one female, one male. This year, with my Cochins--it LOOKS like I only have ONE male & FIVE females. Is that possible???

Could I be THAT lucky??

I can get pics...but I was just noticing it last night...that 1 of the 5 was developing little red wattles & none of the others have them....

 

[patandchickens]

If the male-female odds are 50-50, the chances of 1 male 5 females is (I think) one-half to the fourth power, i.e. 1 in 32 or about 3%. (Math geek note: I've done the one-tailed calculation because the opposite possibility (1 female, 5 males) is quite different from your perspective

) I do not absolutely swear to this, since although I had several years of grad school stats courses, I also basically suck at math <g>

So it is on the one hand somewhat unlikely, but on the other hand not unlikely enough that you should rush out to buy lottery tickets

Glad things seem to be turning out the way you wanted,

Pat

 

[Rare Feathers Farm]

Well...I just couldn't believe it...unless it's the dominant male that has grown the red wattles & there are others (other males) but they haven't grown any wattles because they are lower on the totem pole?

I'll have to post pics of all of the babies...

I also have a Light Brahma which is unsexed, but I'm hoping is a pullet...along with a trio of Buff Orpingtons...which I think is a 1.2?

 

[ticks]

Quote:

your smarter than my algabra teacher

oh, and I got 7 hens out of 7 chicks!

 

[Kev]

One thing to keep in mind about ratios is that they become apparent in LARGE sample numbers- for chicks it would be best to analyze the ratio with 100 chicks or so. 2 and 5 are far too low to show expected/"normal" ratios and become much more mere chance.

You can play with "ratio" for a small sample size right now over and over.. by using a coin. Compare with how many times it falls heads up or tails up. Toss 5 times, and you will get anything from all tails to all heads and everything in between. However you toss 100 times and the results should come out close to 50=50.

 

[Lobzi]

According to my Dad who was raised on a farm with plenty of chickens, it is not a 50/50 chance. More hens to roos is the more likely ratio....not sure that the exact number is however.

 

[Rare Feathers Farm]

Quote:

your smarter than my algabra teacher

oh, and I got 7 hens out of 7 chicks!

Yeah, I was lost like after the first sentence!

 

[Rare Feathers Farm]

Quote:
Thanks! My hubby guessed 50/50 because I do only have 6 chicks (I had seven hatch but one died about 24 hours later). I'll see if I can wrassle them tonight & get some pics of their little faces & combs. I'll also include my others (the Light Brahma & Buff O's...)

 

[Rare Feathers Farm]

Quote:
My hubby said that...he thought that the odds were 50/50 for males to females in smaller numbers, but then he added that they are "usually" females. He was raised on a farm/ranch with poultry...so he knows more about that than I do!

 

[silkiechicken]

Quote:
Yep, if I remember anything from stats, that sounds right.

For one bird, it has a 50/50 chance of being male/female. Like a quarter toss. When you get a large enough sample, per group there will be a Gaussian distribution, with the mid point being 50% boys or girls. However, don't think anyone has calculated the confidence interval of that stat though.