48. Exam grades: Scores on a statistics final in a large class were normally distributed with a mean of 75 and a standard deviation of 8. a. What proportion of the scores were above 90? b. What proportion of the scores were below 65? c. What is the probability that a randomly chosen score is between 70 and 80?
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Given that the mean (μ) is 75 and the standard deviation (σ) is 8, we have: \(Z = \frac{90 - 75}{8} = 1.875\) Show more…
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