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lovecare
Oct 8, 2008, 12:28 PM
Hello


could any one help me in this?? /


the following table shows the distribution of blood types in the general population
A B AB O TOTAL
Rh+ 34% 9% 4% 38% 85%
Rh- 6% 2% 1% 6% 15%
Total 40 11 5 44 100


mY question is



a) What is the probability a person will be Rh- given she or he has type O blood ?

b) What is the probability a person will have type B blood given he or she is Rh+ ?

garcon81
Oct 10, 2008, 08:49 AM
An easy way to think about it is to take the table above and assume each percentage point corresponds to one person - so, 100 people total. Then,

a) There are 44 people with blood type O - 38 of them are Rh+, and 6 are Rh-. Then the odds of being Rh- with type O blood are 6/44.

b) Similarly - 85 people are Rh+. 9 of them have blood type B, so 9/85 is the probability.