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I think that I am doing it right, but I am not sure. Out of 3 children there are 7 possibilities of having a girl out of 8 possible outcomes. I am dividing the 7 possibilities of having a girl by 3 children: 7/3=2.33. I am not real good at this, therefore, is the expected number of girls in a family of 3 the 2.3 I came up with or am I doing this completely wrong? Thank you for any help that I can get!

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    It **cannot** be right. If it were, the expected number of boys would also be $7/3$, giving an expected family size of $14/3$!2012-12-03

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