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Gia0614
04-01-2006, 11:08 PM
:eek: Need help with these two. Have tried and tried and tried.

Q1
Recent developments appear to make it possible for couples to dramatically increase the likelihood that they will conceive a child with the gender of their choice. In a test of a gender method 11 couples are trying to have a baby girl.
If this gender selection has no effect, what is the probability that the 11 babies will all be girls?



Q2
The table below shows the results of administering a diagnostic test for early virus infection.

Positive Test Result Negative Test Result
(Infection Indicated) (Infection Not Indicated)
Subject is infected 84 8
Subject is not infected 7 13

If two different subjects are randomly selected, find the probability that they both test positive.

jerryb
04-03-2006, 09:01 AM
might be too late,

Q1 =P(girl)^11 or virtually zero

Q2 = P(test positive)= (84+7)/(92+21)

P( both Positive) = P(test positive) ^2