Question

The recovery rate from a flu is 0.6. For 4 people having this flu, find the probability that:
(a) All will recover:
(b) Exactly 2 will recover:
(c) At least 2 will recover:
Assume independence Answers should be exact

Answer 1

R= person will recover from flu ---> P(R)=0.6
D = person will not recover from flu --> P(D)=0.4
the events are independent.
a). P(RRRR) = P(R).P(R).P(R).P(R)-->(0.6)^4
b). C(4,2)=6 P(RRDD)= (0.6)(0.6)(0.4)(0.4)(6)=....
c).P(RRRD) = (0.6)(0.6)(0.6)(0.4)=....