SOLUTION: The probability that a patient is allergic to penicillin is .20. If this drug is given to eight patients, find the probability that each of the following is true. Round all answe

Algebra ->  Probability-and-statistics -> SOLUTION: The probability that a patient is allergic to penicillin is .20. If this drug is given to eight patients, find the probability that each of the following is true. Round all answe      Log On


   

Question 1150331: The probability that a patient is allergic to penicillin is .20. If this drug is given to eight patients, find the probability that each of the following is true. Round all answers to four decimal places.
a. three of the eight are allergic.
b. none of the eight are allergic.
c. at least four are allergic.
d. between two and five of the eight are allergic.
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


For each patient,
P(allergic) = 0.20
P(not allergic) = 0.80

Then

P(n of 8 are allergic) = %28C%288%2Cn%29%29%2A%28%280.20%29%5En%29%2A%28%280.80%29%5E%288-n%29%29

Between the four questions that are asked, you need to calculate the probability that nearly any number of the eight are allergic. So you might as well calculate all the probabilities and verify that their sum is 1; that will give you some reassurance that you have made all the calculations correctly.

a. 3 of 8 allergic



You can do the others....