SOLUTION: Approximately 10.3% of American high school students drop out of school before graduation. Choose 10 students entering high school at random. Find the probability that a. No more

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Question 1124654: Approximately 10.3% of American high school students drop out of school before graduation. Choose 10 students entering high school at random. Find the probability that
a. No more than two drop out
b. At least 6 graduate

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Probability of 0 drop outs is .897^10=0.3372
1 drop out is 10*.103*.897^9=0.3872
2 drop outs is 45 (10C2)*.103^2*.897^8=0.2001
That sum is 0.9245
So probability no more than 2 drop out in the sample is 0.9245
for 3 it is 120*.103^3*.897^7=0.0613
for 4 it is 210*.103^4*.897^6=0.0123. This is 6 graduating
The probability of 0-4 dropouts, which is at least 6 not dropping out is 0.9981.
The expected value is about 1 and the sd is about 0.95