1) 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 60thpercentile 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.

2) Researchers studying the effects of a new diet found that the weight loss over a one-month period by those on the diet was normally distributed with a mean of 9 pounds and a standard deviation of 3 pounds.

• What proportion of the dieters gained (did not lose) weight?