Use the binomial theorem for these problems,
In your case n = 18 & p= 0.6
a) P(X=15)+P(X=16)+P(X=17)+P(X=18)
b) P(X=5)+P(X=6)+P(X=7)+P(X=8)+P(X=9)+P(X=10)
c) P(X=12)
I don't think your attempt for part a) is very robust.
Hello people I have this problem to solve.
The probability that a patient recovers from a rare blood disease is 0.6. If 18 people are known to have contracted this disease, what is the probability that:
(i) at least 15 survive?
p=0.6
15/18*0.6=0.5, 50%
(ii) from 5 to 10 survive?
(iii) Exactly 12 survive?
(I have attempted the first part not sure if it is correct. Really appreciate replys in regads to the answer).