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Chapter 6: Q. 3.3 (page 393)

Refer to the previous Check Your Understanding (page 390) about Mrs. Desai's special multiple-choice quiz on binomial distributions. We defined X=the number of Patti's correct guesses.

3. What's the probability that the number of Patti's correct guesses is more than 2standard deviations above the mean? Show your method.

Short Answer

Expert verified

Patti's correct estimates had a 0.322 chance of being more than2 standard deviations above the mean.

Step by step solution

01

Given Information

Number of questions=10

Students are supposed to guess the answers.

Xis a number of answers that Patti gives correct.

Probability of success(p)=0.2

02

Explanation 

We can compute the probability of more than 2correct answers by using the formula below, :

P(X>2)=∑r=210Cr10×(0.2)r×(1-0.2)10-r=0.322.

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Most popular questions from this chapter

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