document.write( "Question 194910: A couple plan to have exactly four children.
\n" ); document.write( "a) construct a tree diagram and list the sample space.
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Algebra.Com's Answer #146225 by Mathtut(3670)\"\" \"About 
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this says at least 3 boys so we would follow all branches that have 3 or 4 boys and add the probabilities together: out of the Boys portion , we have 3 branches that lead to 3 or more boys
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\n" ); document.write( "in the girls part of the tree only one branch leads to 3 or more boys
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\n" ); document.write( ".5*.5*.5*.5+.5*.5*.5*.5+.5*.5*.5*.5+.5*.5*.5*.5=.0625+.0625+.0625+.0625=.25
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\n" ); document.write( "so a 1 in 4 chance of 3 or more boys
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