Question

Let B be the number of 2 boys in a family of four children. Construct the probability distribution for the random variable B

Answer 1

b = boys

g = girls

The possible outcomes for B are 0, 1, 2.

0 or 1 boy (B=0):

gggg

bggg

gbgg

ggbg

gggb

2 boys (B=1):

bbgg

ggbb

gbbg

bggb

gbgb

bgbg

4 boys (B=2):

bbbb