Quiz

$e_{T+h}$ is the estimated value of the random shock component, $\epsilon_{T+h}$, of an ARIMA model.

$e_{T+h}$ is the difference between the actual value of the series, $y_{T+h}$, and its predicted value, $\hat y_{T+h}$.

$e_{T+h}$ is the output of the loss function that we use to get the best prediction for $y_{T+h}$.

$e_{T+h}$ is the difference between the predictions of two ARIMA models.