1 answer
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Step 1: Find the mean of the quiz grades
Mean = (91 + 92 + 94 + 88 + 96 + 99 + 91 + 93 + 94 + 97 + 95 + 97) / 12
Mean = 1153 / 12
Mean = 96.08 (rounded to 2 decimal places)
Step 2: Find the standard deviation of the quiz grades
Using a calculator or software, we can find the standard deviation to be 3.58 (rounded to 2 decimal places)
Step 3: Calculate the range of grades that fall within one standard deviation of the mean
96.08 + 3.58 = 99.66
96.08 - 3.58 = 92.50
Therefore, all the quiz grades fall within one standard deviation of the mean, which is between 92.50 and 99.66.