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5 votes
In Mr. Smith's 7th Hour

class there are 16 boys and
7 girls. What is the
probability of randomly
selecting a boy?

User Dipu
by
3.0k points

1 Answer

7 votes

binomial(16 + 7, 16) 2^(-(16 + 7)) = ((16 + 7)!)/(16! 7! 2^(16 + 7)) = 245157/8388608 ≈ 0.02922 ≈ 1/34.22

(assuming children are independent and male and female are equally likely)

| probability

less than 16 boys | 0.9534

16 or less boys | 0.9827

more than 16 boys | 0.01734

16 or more boys | 0.04657

fraction of boys | 16/(16 + 7) ≈ 0.695652

fraction of girls | 7/(16 + 7) ≈ 0.304348

expected value | 11.5

standard deviation | 2.398

variance | 5.75

11.5

User Axelferreira
by
3.5k points