SOLUTION: A test consists of 10 true of false questions. To pass the test a student must answer at least eight questions correctly. If the student guesses on each question. What is the proba

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Question 1103074: A test consists of 10 true of false questions. To pass the test a student must answer at least eight questions correctly. If the student guesses on each question. What is the probability that the student will pass the test?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
10 questions.
T/F so the probability of correct answer is 0.5.
Find P(8), P(9), and P(10).
.
.
.
P%28X%29=C%2810%2CX%29%2A%280.5%29%5EX%2A%280.5%29%5E%2810-X%29
P%28X%29=C%2810%2CX%29%2A%280.5%29%5E%2810%29
P%28X%29=C%2810%2CX%29%2F2%5E10
P%288%29=C%2810%2C8%29%2F2%5E10=45%2F1024
P%288%29=C%2810%2C9%29%2F2%5E10=10%2F1024
P%288%29=C%2810%2C10%29%2F2%5E10=1%2F1024
So,
P=P%288%29%2BP%289%29%2BP%2810%29
P=%2845%2B10%2B1%29%2F1024
P=56%2F1024
P=7%2F128