SOLUTION: Could you help me with this Please? 9. (6 pts) A couple plan to have exactly three children. (a) Construct a tree diagram and list the sample space. View this --> http://col

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Question 145211This question is from textbook
: Could you help me with this Please?
9. (6 pts) A couple plan to have exactly three children.
(a) Construct a tree diagram and list the sample space.
View this --> http://collabvsl.wetpaint.com/page/Basic+Probability
(b) Find the probability that the family has at least two girls.
This question is from textbook

Answer by vleith(2983) (Show Source):
You can put this solution on YOUR website!
Is too hard to draw the tree here. That video has a good one in it.
As far as probability goes
there is 1/4 chance the first 2 are both girls. Thus there is a 3/4 chance the first two are not both girls.
So we have 1/4 + (3/4)*(1/2) = 1/4 + 3/8 = 1/2
If you draw the tree and count those branches with at least 2 girls on it, you'll see there are four of them. Since there are 8 possible outcomes, that is also a way to get to 4/8 = 50%