Question

In: Statistics and Probability

Scores on Professor Combs' Statistics Final Exams have a long term history of being normally distributed,...

Scores on Professor Combs' Statistics Final Exams have a long term history of being normally distributed, with a mean of μμ = 72 and a standard deviation of σσ = 9

a.) Find the probability that a single student will score above a 77 on the Final exam.

b.) Find the probability that a single student will score between a 67 and 77 on the Final exam.

c.) Find the probability that an entire class of 20 students will have a class average above a 77 on the exam.

d) Find the probability that an entire class of 20 students will have a class average between 67 and 77 on the Final exam.

Solutions

Expert Solution

Refer Standard normal table/Z-table to find the probability or use excel formula "=NORM.S.DIST(0.5556, TRUE)" to find the probability.

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Refer Standard normal table/Z-table to find the probability or use excel formula "=NORM.S.DIST(0.5556, TRUE)" & "=NORM.S.DIST(-0.5556, TRUE)" to find the probability.

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Refer Standard normal table/Z-table to find the probability or use excel formula "=NORM.S.DIST(2.4845, TRUE)" to find the probability.

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Refer Standard normal table/Z-table to find the probability or use excel formula "=NORM.S.DIST(2.4845, TRUE)" & "=NORM.S.DIST(-2.4845, TRUE)" to find the probability.

orchestra answered 2 years ago
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