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carebear70417
10-09-2005, 09:08 PM
Assume that male and female births are equally likely and that the birth of any child does not affect the probability of the gender of an other children. Find the probability of exactly eight boys in ten births.

(a).176
(b).044
(c).8
(d).08

To do this problem would you just divide 8 by 10 or would you do p1+p2......+p8?

JohnM
10-09-2005, 09:22 PM
The probability of a male birth = 0.5, and so the probability of a female birth is 0.5 also.

This problem requires you to use the binomial formula, and is exactly like a problem that asks you to find the probability of exactly 8 heads when you flip a coin 10 times.

P(x=r) = nCr * p^r * (1-p)^n-r

r=8
n=10
p=0.5

Your course textbook should have an example of this.....