00:01
Not to answer this question, let's talk about inheritance.
00:03
It says, assuming a one -to -one birth ratio, the loss of probability predict that half of the children in a family will be boys and a half will be girls.
00:12
So practically, you have 50 % chances in each pregnancy to get a boy and 50 % chances in a pregnancy to get a girl.
00:23
So 50 % is the same as one half.
00:25
So you have one -half chances to get a boy and one -half chances to get a girl.
00:29
And it says, what is the probability that this expected outcome home good up in a family of four children.
00:34
So you have one, two, three, and four children.
00:39
And you want a one -to -one ratio.
00:43
It means you want that half of the children here are boys and half of the children here are girls.
00:49
So you want this, for example, boy, boy, girl, and girl.
00:53
But not necessarily in disorder, because another combination can be boy, girl, boy, girl.
01:00
So you can have many combinations.
01:01
But the good thing here is that each of these pregnancies is going to have one -half chances to get a girl and one -half chances to get a boy.
01:10
So you have one -half here, one -half, one -half, and one -half.
01:15
So you have to multiply all of them and you're going to get one -sixteenth.
01:19
Now, the order of the factors does not alter the product.
01:22
In this case, it doesn't matter if you change this b here and this g here and so on because the order or the product is going to be the same.
01:31
Okay, so in this case you have one half, one half, one half, one half, and one half.
01:34
So you have also one 16s.
01:37
So you have one 16s.
01:39
But how many different combinations do you have? well, in this case, you have to use a following formula that is like this.
01:50
And it's a total amount of objects in this set.
01:53
You have four children and you have two groups.
01:57
This is one group and this is another group.
01:59
You want a group of two boys and a group of two girls.
02:02
So you have two factorial, multiply by two factorial.
02:05
2 factorial is equal to 2 multiplied by 1, so it is equal to 2 multiplied by 2 practically...
