## Root Mean Squared Error (RMSE)

Submissions are scored on the root mean squared error. RMSE is defined as:

$$
\text{RMSE} = \sqrt{\frac{1}{N} \sum_{i=1}^N (y_i - \hat{y}_i)^2}
$$

Where:

- `ŷ_i` is the predicted value,
- `y_i` is the actual value for each instance `i`,
- `N` is the total number of instances.