SOLUTION: 1. We know that the probability of correctly responding to a multiple choice question while guessing is 0.25 if there are four answer choices. Suppose a test has 20 questions. We

Question 797258: 1. We know that the probability of correctly responding to a multiple choice question while guessing is 0.25 if there are four answer choices. Suppose a test has 20 questions. We also know that correctly responding follows a binomial distribution for this test.
what is the mean and standard deviation?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
We know that the probability of correctly responding to a multiple choice question while guessing is 0.25 if there are four answer choices. Suppose a test has 20 questions. We also know that correctly responding follows a binomial distribution for this test.
what is the mean and standard deviation?
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mean = np = 20*0.25 = 5
std = sqrt(npq) = sqrt(5*0.75) = 1.9365
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Cheers,
Stan H.
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