exercise 2.31. suppose a family has 2 children of different ages. we assume that all combinations of boys and girls are equally likely. (a) formulate precisely the sample space and probability measure that describes the genders of the two children in the order in which they are born. (b) suppose we learn that there is a girl in the family. (precisely: we learn that there is at least one girl.) what is the probability that the other child is a boy? (c) suppose we see the parents with a girl, and the parents tell us that this is their youngest child. what is the probability that the older child we have not yet seen is a boy?



Answer :

PNaik

A.  P(BB) = P( GG) ,P(BG), P(GB) .1/4 the sample space and probability measure that describes the genders of the two children in the order in which they are born.

B.    = 1/2 is the probability that the other child is a boy.

C.   1/2 is the probability that the older child we have not yet seen is a boy.

A. sample space s. {BB,GG,BG,GB}

    P(BB) = P( GG) ,P(BG), P(GB) .1/4

B. P(other child is boy / at least one girl

therefore P(A/B) = P(A∩B)/P(B)      ( Additional probe)

P(B) = P (at least one girl)

      = P (GG)+P(BG)+P(GB)

      = 1/4+1/4+1/4

      = 3/4

P (A∩B) = P (One boy and one girl)

             = P (BG)+P(GB)

             = 1/4+ 1/4

            = 1/2

Therefore, P(A/B) = [tex]\frac{\frac{1}{2} }{\frac{3}{4} }[/tex] = 2/3

C. P (older child is a boy/ younger child is a girl)

   P [tex]\frac{older child\ is a\ boy}{youngerchild is a girl}[/tex]

P(BG)/P (BG)+ P (GG) = 1/4/1/4+1/4 = 1/2

What is probability?

Probability refers to potential. A random event's occurrence is the subject of this area of mathematics. The range of the value is 0 to 1. Mathematics has incorporated probability to forecast the likelihood of various events. The degree to which something is likely to happen is basically what probability means. You will understand the potential outcomes for a random experiment using this fundamental theory of probability, which is also applied to the probability distribution. Knowing the total number of outcomes is necessary before we can calculate the likelihood that a specific event will occur.

To learn more about probability, refer;

https://brainly.com/question/14210034

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