14Apr/103
What is the chance that 3 children received the same X chromosome from their mother?
That is, the mother had XaXb, what is the chance that 3 of her children all received Xa. What probabilities would go into solving this problem?
That is, the mother had XaXb, what is the chance that 3 of her children all received Xa. What probabilities would go into solving this problem?
April 14th, 2010 - 07:10
Since the mother gives 2 Xa out of 4 possibilities of a child…
Each child with Xa is a probability of 1/2 so….
X Y
Xa XaX XaY
Xb XbX XbY
So 3 children (chances) is 1/2 x 1/2 x 1/2 or (1/2)^n, n is # chances
Answer:
1/8
April 14th, 2010 - 07:48
Well, there is a 50% chance for the first child. Same for all the other children. So, you must multiply the odds to get the probability that all three children will get it:
0.5 * 0.5 * 0.5 = 0.125
So there is a 12.5% chance that all three children will get it. Note that it wouldn’t matter if the child was a girl or a boy, since they would both get only one X chromosome from the mother.
April 14th, 2010 - 08:44
each child has a 1/2 (or 50%) chance of receiving the same X chromosome. The chance of ALL THREE receiving the same X chromosome is (1/2) times (1/2) times (1/2)= 1/8
and 1/8 is the same as 12.5%