newbie4000
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- May 14, 2020
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In a multiple-choice test, the probability that you know the answer to a question is 0.6. If you do not know the answer, you choose one at random. Suppose that there are 10 questions in the test and let C be the number of multiple choices per question (the test will have all the questions having the same number of choices C). Before taking the test, you do not know the value of C, but you know that it can be either 3 or 4, with probability 0.3 and 0.7 respectively.
a)Find the probability that you know the answers to at least 80% of the questions.
b) Assume that C = 3. Find the conditional probability that you answer at least 90% of the questions correctly, given that you know the answers to at least 80% of the questions.
c) Repeat part (b), but now assume that C is either 3 or 4, with probability 0.3 and 0.7, respectively.
for part (a) i did binomial distribution which gets me a value of 0.1616
i have no idea of how to do part b and c except knowing that it needs to use conditional probability
a)Find the probability that you know the answers to at least 80% of the questions.
b) Assume that C = 3. Find the conditional probability that you answer at least 90% of the questions correctly, given that you know the answers to at least 80% of the questions.
c) Repeat part (b), but now assume that C is either 3 or 4, with probability 0.3 and 0.7, respectively.
for part (a) i did binomial distribution which gets me a value of 0.1616
i have no idea of how to do part b and c except knowing that it needs to use conditional probability