Final answer:
The mean absolute deviation, given the forecast errors of 4, 8, and -3, is calculated by taking the absolute values, summing them, and dividing by the number of errors, resulting in a mean absolute deviation of 5.
Step-by-step explanation:
The question asks to calculate the mean absolute deviation given forecast errors of 4, 8, and -3. The mean absolute deviation is calculated by taking the absolute values of the errors, summing them up, and then dividing by the number of errors. The absolute values are 4, 8, and 3 (note that we take the absolute of -3, which is 3). Adding these up, we get 4 + 8 + 3 = 15. Since there are three errors, we divide by 3, which gives us a mean absolute deviation of 15 / 3 = 5.