4 Ebola patients are to be treated with a new serum. The probability of success with this serum is 0.4. What is the probability of only 2 successful treatments?

Question

• 4 Ebola patients are to be treated with a new serum. The probability of success with this serum is 0.4. What is the probability of only 2 successful treatments? Show appropriate formula and calculations.

Answer 1

n = 4, p (probability of success)= 0.4 and X (# of success)= 2

Required probability = C(4, 2)*(0.4)²*(0.6)² = 0.3456

If you are using TiNspire CX CAS calculator,

go calc > Menu > 5 > 5 > D and plug in n, p and X in that order. The display would be

binomPdf(4, 0.4, 2) = 0.3456