On a 10-item test, three students in Professor Hsin's advanced chemistry seminar received scores of 2, 5, and 8, respectively. For this distribution of test scores, the standard deviation is equal to the square root of

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Quizplus · Accepted Answer

The variance is the average of the squared differences from the mean. The mean is (2+5+8)/3 = 5. The squared differences from the mean are (2-5)^2 = 9, (5-5)^2 = 0, and (8-5)^2 = 9. The variance is (9+0+9)/3 = 6. The standard deviation is the square root of the variance, which is sqrt(6) = 2.45.

On a 10-Item Test, Three Students in Professor Hsin's Advanced