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 one year ago
What is the probability that out of 125 babies born, at least 70 will be girls? Assume that boys and girls are equally probable, and round your answer to the nearest tenth of a percent. A.99.0% B.70.4% C.10.5% D.51.2%
 one year ago
What is the probability that out of 125 babies born, at least 70 will be girls? Assume that boys and girls are equally probable, and round your answer to the nearest tenth of a percent. A.99.0% B.70.4% C.10.5% D.51.2%

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FeoNeo33
 one year ago
Best ResponseYou've already chosen the best response.010 20 30 40 50 60 70 / 80 90 100 110 120 ...125 70 / 50... Which I pick... B.

FeoNeo33
 one year ago
Best ResponseYou've already chosen the best response.0By the way, I made up that way to get the answer, not a real technique.

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0im thinking it sounds like a binomial probability setup

Jovanmommy_13
 one year ago
Best ResponseYou've already chosen the best response.0that what these are

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0125 C 70 times success^(70) times failure^(12570) 125 C 70 (1/2)^(70) (1/2)^(12570) soo:\[\sum_{k=70}^{125}\binom{125}{k}.5^{k}.5^{125k}\]

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0or we can try a normal approximation :)

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0mean = np = 125(.5) = 62.5 so we would expect 62.5 of the population to be girls sd = sqrt(npq) = sqrt(62.5*.5) = sqrt(31.25)

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0do you have to do this all by hand or do you have a ti83?

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0\[z=\frac{xmean}{sd}\] \[z=\frac{7062.5}{\sqrt{31.25}}=1.34\] looking on a ztable; that corresponds to about 100%  91%

amistre64
 one year ago
Best ResponseYou've already chosen the best response.0so yeah, it aint gonna be B, but it does look like it will be close to 10%
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