SOLUTION: a recent survey found that 70% of all adults over 50 wear glasses for driving. In a random sample of 10 adults over 50, what is the probability that at least six wear glasses

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Question 666297: a recent survey found that 70% of all adults over 50 wear glasses for driving. In a random sample of 10 adults over 50, what is the probability that at least six wear glasses
Answer by swincher4391(1107) About Me  (Show Source):
You can put this solution on YOUR website!
Use the binomial distribution since you can either wear glasses or you don't wear glasses. Trials are independent since glasses on one doesn't effect the other.
P[x>=6] = P[x=6]+P[x=7]+P[x=8]+P[x=9]+P[x=10]
(10 choose 6) * (.70)^6 *(.30)^4 + (10 choose 7) * (.70)^7 * (.30)^3 + (10 choose 8) * (.70)^8 *(.30)^2 + (10 choose 9) * (.70)^9 * (.30)^1 + (10 choose 10) *(.70)^10 * (.30)^0 = .8497