Suppose that a quiz consists of 20 true-false questions.A student has not studied for the exam and just randomly guesses the answers.How would you find the probability that the student will get 8 or fewer answers correct?
A.Find the probability that X=8 in a binomial distribution with n=20 and p=0.5.
B.Find the area between 0 and 8 in a uniform distribution that goes from 0 to 20.
C.Find the probability that X=8 for a normal distribution with mean of 10 and standard deviation of 5.
D.Find the cumulative probability for 8 in a binomial distribution with n=20 and p=0.5.
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2.Answer:D
Explanation:A binomial distribution is a probability distribution,and it refers to the various probabilities associated with the number of correct answers out of the total sample.
The correct approach is to find the cumulative probability for 8 in a binomial distribution with N=20 and p=0.5.
The cumulative probability is to be calculated on the basis of a binomial distribution with number of questions
(n)equaling 20 and probability of a singleevent occurring being 50%(p=0.5).
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