At a particular hospital,records show that each day, on average,80% of people keep their appointment at the outpatient's clinic. i)Find the probability that in a random sample of 10 patients, more than 7 keep their appointment.

Answer 1

prob(keep) = 80/100 = 4/5
prob(not keep) = 1/5

prob(10 patients, more than 7 keep their appointment.)
= prob(8 will keep) + prob(9 will keep) + prob(10 will keep)
= C(10,8) (4/5)^8 (1/5)^2 + C(10,9) (4/5)^9 (1/5) + C(10,10) (4/5)^10 (1/5)^0
= 45(.16777216)(.04) + ...... + 1(.107374182)(1)
= ....

let me know what you get