Final answer:
To find the mean absolute deviation of Donna's brothers' ages, calculate the mean of the ages and the absolute deviation of each age from the mean.
Step-by-step explanation:
The mean absolute deviation (MAD) measures the average distance between each data point in a dataset and the mean of the dataset. To find the MAD of Donna's brothers' ages, we need to calculate the mean of the ages first. Let's say Donna's brothers' ages are 20, 13, and 33.
The mean of these ages is (20 + 13 + 33) / 3 = 22. The next step is to find the absolute deviation of each age from the mean: |-20| = 7, |-13| = 9, and |-33| = 11. Finally, we calculate the mean of these absolute deviations: (7 + 9 + 11) / 3 = 9. Therefore, the mean absolute deviation of Donna's brothers' ages is 9 years.