We flip a fair coin 10 times. What is the probability that we get heads in at least 8 of the 10 flips?
+128474
"At least eight" means eight or more....this is a binomial probability problem....and we have
P ( 8 heads) = C(10,8) * .5^8 * .5^2
P(9 heads) = C(10,9) * .5^9 * .5
P(10 heads) = .5^10
So.....the total probability is
C(10, 8) *.5^8 * .5^2 + C(10,9) * .5^9 * .5 + .5^10 = 7/128 ≈ .0547 ≈ 5.47%
