# There are 80 questions from an SAT test, and they are all multiple choice with possible answers of a, b, c, d, e. For each question, only one answer is correct. Find the mean and standard deviation for the numbers of correct answers for those who make random guesses for all 80 questions.

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There are 80 questions from an SAT test, and they are all multiple choice with possible answers of a, b, c, d, e. For each question, only one answer is correct. Find the mean and standard deviation for the numbers of correct answers for those who make random guesses for all 80 questions.

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Step 1

Computation of mean:

Here, there are n trials; there are only 2 possible mutual outcomes (Correct or incorrect answer); the probability of success remain same for each outcome; trials are independent of each other. Thus, the given scenario follows binomial distribution.

The number of que...

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