If 20 of people in a community use the emergency room at a h

If 20% of people in a community use the emergency room at a hospital in one sear, find these probabilities for a sample of 12 people. At most three used the emergency room. Exactly three used the emergency room At least five used the emergency room.

Solution

p = 20% = 0.2

n = 12

X no of people using emergency room is binomial

a) P(X<=1)=0.2749

b) P(x=3)=0.2362

c) P(X>=5) =0.0726