A philosophy professor decides to give a 20 question multiple-choice quiz to determine who has read...

A philosophy professor decides to give a 20 question multiple-choice quiz to determine who has read an assignment. Each question has 3 choices. Let Y be the random variable that counts the number of questions that a student guesses correctly. You can assume that questions and answers are independent.

Find the probability distribution function of Y by making a table of the possible values of Y and their corresponding probabilities.
Add a column for the Cumulative Distribution Function (CDF) for each value of X.
Find the expected value and standard deviation of Y.
If she wants to choose a passing grade such that the probability of passing a student who guesses at every question is less than 0.05, then what score should she set as the lowest passing grade?

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orchestra answered 1 year ago

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