To find the mean absolute deviation, first calculate the mean of Lucia's grades:
(74 + 81 + 86 + 92 + 74 + 85 + 90 + 89 + 78 + 80) / 10 = 829 / 10 = 82.9
Next, find the absolute deviation of each grade from the mean:
|74 - 82.9| = 8.9
|81 - 82.9| = 1.9
|86 - 82.9| = 3.1
|92 - 82.9| = 9.1
|74 - 82.9| = 8.9
|85 - 82.9| = 2.1
|90 - 82.9| = 7.1
|89 - 82.9| = 6.1
|78 - 82.9| = 4.9
|80 - 82.9| = 2.9
Add up all the absolute deviations and divide by the number of grades (10) to find the mean absolute deviation:
(8.9 + 1.9 + 3.1 + 9.1 + 8.9 + 2.1 + 7.1 + 6.1 + 4.9 + 2.9) / 10 = 55 / 10 = 5.5
Therefore, the mean absolute deviation of Lucia's Spanish quiz grades is 5.5.
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)
Responses
55
55
5.5
5.5
82.9
82.9
8.29
1 answer
1 answer