Question

Plz help ASAP!! A surgical technique is performed on eight patients. You are told that there is an 80% chance of success. Find the probability that the surgery is successful for fewer than two patients. Please show your work. Hint: the answer is 0.000084.

Answer 1

This is a fairly simple binomial distribution. We know it's binomial, because we're looking for a "fixed" number of patients, not the "first" like a geometric.

You can use your calculator:

binomcdf(n,p,Kr)

n=population, p=probability, Kr=number you're looking for

binomcdf(8,.8,1)

We have to do 1, not 2, because it says fewer than 2, which means 1.

= 8.448 x 10⁻⁵ = .00008448, which is approximately the answer given!