Question

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.

Answer 1

1/3??
15% of 80 is 12. So 12 donors have B blood type. Between 15%(12) to 20%(16), there are four members. So probability that these four members are in those 12 B blood type donors is 4/12 = 1/3

Answer 2

I really think it's 1/3