Lucia has been recording her grades on her Spanish quizzes. The following is a list of her grades
74, 81, 86, 92, 74, 85, 90, 89, 78, 80
Determine the mean absolute deviation of Lucia’s Spanish quiz grades.
(1 point)
To find the mean absolute deviation, first find the mean of Lucia's quiz grades:
(74 + 81 + 86 + 92 + 74 + 85 + 90 + 89 + 78 + 80) / 10 = 835 / 10 = 83.5
Next, find the absolute deviations from the mean for each grade:
|74 - 83.5| = 9.5
|81 - 83.5| = 2.5
|86 - 83.5| = 2.5
|92 - 83.5| = 8.5
|74 - 83.5| = 9.5
|85 - 83.5| = 1.5
|90 - 83.5| = 6.5
|89 - 83.5| = 5.5
|78 - 83.5| = 5.5
|80 - 83.5| = 3.5
Now, find the average of these absolute deviations:
(9.5 + 2.5 + 2.5 + 8.5 + 9.5 + 1.5 + 6.5 + 5.5 + 5.5 + 3.5) / 10 = 54 / 10 = 5.4
Therefore, the mean absolute deviation of Lucia's Spanish quiz grades is 5.4.