Question

The grades on the final examination given in a large organic chemistry class are normally distributed with a mean of 72 and a standard deviation of 8. The instructor of this class wants to assign an “A” grade to the top 10% of the scores, a “B” grade to the next 10% of the scores, a “C” grade to the next 10% of the scores, a “D” grade to the next 10% of the scores, and an “F” grade to all scores below the 60^th percentile of this distribution. For a letter grade of A, find the lowest acceptable score within the established range. Provide your answer in the format XX.X, for example, 93.4.

Answer 1

The detailed solution is given in the pictures below.

Please go through them carefully specially the notations.

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