SOLUTION: Among 46-51-year-olds, 28% say they have written an editorial letter while under the influence of peer pressure. Suppose six 46-51-year-olds are selected at random. (a) The p

Algebra ->  Probability-and-statistics -> SOLUTION: Among 46-51-year-olds, 28% say they have written an editorial letter while under the influence of peer pressure. Suppose six 46-51-year-olds are selected at random. (a) The p      Log On


   



Question 947461: Among 46-51-year-olds, 28% say they have written an editorial letter while under the influence of peer pressure. Suppose six 46-51-year-olds are selected at random.
(a) The probability that at least one of the six randomly selected adults has not written an editorial letter while under the influence of peer pressure.
Correct answer = 1 - (28)^6 = 0.999518
(b) The probability that at least one of the six randomly selected adults has written an editorial letter while under the influence of peer pressure.
This is the example that I am having issues with. The answer given is = 0.8607. No matter how I've done the math, I cannot come to 0.8607. Details would be appreciated.

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
if 28% or 0.28 say no, to compute the probability that at least one of six has not written an editorial letter while under the influence of peer pressure is %280.28%29%280.28%29%280.28%29%280.28%29%280.28%29%280.28%29=%280.28%29%5E6 and subtract it from 1. This is the same as at least 1 has not written an editorial letter while under the influence of peer

1-%280.28%29%5E6+=1-0.000481890304+=0.999518109696=0.999518 has not written an editorial letter while under the influence of peer pressure
(b) The probability that at least one of the six randomly selected adults has written an editorial letter while under the influence of peer pressure.
if 0.28 has not written an editorial letter while under the influence of peer pressure, then 72% or 0.72 has written an editorial letter while under the influence of peer pressure
the probability that at least one has written an editorial letter while under the influence of peer pressure is
1-0.72%5E6=1-0.139314069504=0.860685930496=0.8607