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

Discussion in 'Raising Baby Chicks' started by Rare Feathers Farm, Jun 4, 2008.

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  1. Jun 4, 2008 #1
    Rare Feathers Farm

    Rare Feathers Farm Crowing

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    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?? [​IMG]

    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....
     
    Last edited by a moderator: Jun 4, 2008

  4. Jun 4, 2008 #2
    patandchickens

    patandchickens Flock Mistress

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    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 [​IMG]) 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 [​IMG]

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

    Pat
     
  6. Jun 4, 2008 #3
    Rare Feathers Farm

    Rare Feathers Farm Crowing

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    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? [​IMG]

    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?
     
  8. Jun 4, 2008 #4
    ticks

    ticks Pheasant Obsessed

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    Quote:[​IMG] your smarter than my algabra teacher [​IMG]

    oh, and I got 7 hens out of 7 chicks!
     
  10. Jun 4, 2008 #5
    Kev

    Kev Crowing

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    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.
     
  12. Jun 4, 2008 #6
    Lobzi

    Lobzi Crowing

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    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.
     
  14. Jun 4, 2008 #7
    Rare Feathers Farm

    Rare Feathers Farm Crowing

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    Quote:[​IMG] your smarter than my algabra teacher [​IMG]

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

    Yeah, I was lost like after the first sentence! [​IMG]
     

  17. Jun 4, 2008 #8
    Rare Feathers Farm

    Rare Feathers Farm Crowing

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    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...)
     
  19. Jun 4, 2008 #9
    Rare Feathers Farm

    Rare Feathers Farm Crowing

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    Pleasant Valley, (Okanogan) WA
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    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! [​IMG]
     
  21. Jun 4, 2008 #10
    silkiechicken

    silkiechicken Staff PhD Premium Member

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    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.
     
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