posted by Jen on .
The blood types B- and AB- are the rarest of the eight huan blood types representing 1.5% and .6% respectively.
a) If the blood types of a random sample of 1000 blood donors are recorded, what is the probability that 10 or more will be AB-?
b) If the blood types of a random sample of 1000 blood donors are recorded, what is the probability that 20 t 40 inclusive of the samples are B-?
c) If a particular city had a blood drive and 3% of the donations were B-, would we have reason to believe that this town has a higher than normal number of donors who are B-? (Hint: Calculate the probablilty of 15 or more donors being B- for a random sample of 500 and then discuss the probability obtained.)
I suggest that you use the methodology suggested by Mathguru in your next post.