SOLUTION: the proportion of adults 25 and older in a certain country with at least a bachelor's degree is 0.25. suppose you pick seven adults at random. what is the probability that exactly

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Question 1160867: the proportion of adults 25 and older in a certain country with at least a bachelor's degree is 0.25. suppose you pick seven adults at random. what is the probability that exactly three will have a bachelor's degree or higher?
Answer by ikleyn(52879) About Me  (Show Source):
You can put this solution on YOUR website!
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Use the Binomial Probability formula


    Probability (P) (k successes in n trials) = nCk * p^k * (1-p)^(n-k), where nCk = n! / (k! * (n-k)!)



For this problem, n = 7, k = 3, p = 0.25.


    P(exactly three will have a bachelor's degree or higher) = C%5B7%5D%5E3+%2A+0.25%5E3+%2A+%281-0.25%29%5E%287-3%29 = %28%287%2A6%2A5%29%2F%281%2A2%2A3%29%29%2A0.25%5E3%2A0.75%5E4 = 0.1730 = 17.3%.    ANSWER

Solved.