To pass a true or false test a student must answer 8 out of 10 correct. What is the probability a student will pass if he quesses on all 10 questions?
Find the mean and standard deviation of correct answers.

Is it unusual for a student to pass by guessing?

Question

To pass a true or false test a student must answer 8 out of 10 correct. What is the probability a student will pass if he quesses on all 10 questions?
Find the mean and standard deviation of correct answers.

Is it unusual for a student to pass by guessing?

perl · Answer

I can help

perl · Answer

to pass he must score at least 8

perl · Answer

we want P(x>= 8)  , where x is a binomial random variable , x = # of correct answers. for each trial the probability of getting correct on a guess is .50