## Root Mean Squared Error (RMSE)

Submissions are scored on the root mean squared error. RMSE is very common and is a suitable general-purpose error metric. Compared to the Mean Absolute Error, RMSE punishes large errors:

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

where \\( \hat{y}(i) \\) the predicted value and \\( y(i) \\) is the original value.

## Submission File

For every policy in the dataset, submission files should contain two columns: `ClaimNumber` and `UltimateIncurredClaimCost`. 

The file should contain a header and have the following format:

```
ClaimNumber,UltimateIncurredClaimCost
WC8145235,1000.0
WC2005111,1000.0
WC6899143,1000.0
WC4785156,1000.0
WC8145238,1000.0
etc.
```