Approximately 15% of Americans have a blood type of B. The local blood bank has 80 donors stop by on a given day (which can be considered a random sample from the population). What is the probability that between 15% and 20% of the donors on a given day have a blood type of B? Be sure to state and justify your assumptions.

Question

tkhunny · Answer

If you are to justify your assumptions, you should start making some.  What say you?

anonymous · Answer

Well, I have no idea how to even start this

tkhunny · Answer

Super.  Then you are in the wrong class.

If you have a proportion, can you find the standard deviation?  It may have something to do with the Sample Size.  Give it a go.

anonymous · Answer

Oh actually, I see how to do this now. Thanks