The evaluation metric for this competition is Root Mean Square Error ([RMSE](https://en.wikipedia.org/wiki/Root-mean-square_deviation)). RMSE is the standard deviation of the residuals (prediction errors). Residuals are a measure of how far from the regression line data points are; RMSE is a measure of how spread out these residuals are. In other words, it tells you how concentrated the data is around the line of best fit
(see [here](https://www.statisticshowto.com/probability-and-statistics/regression-analysis/rmse-root-mean-square-error/) for further details).

This metric was chosen due to the fact that errors are squared before averaged. This gives a relatively high weight to large errors, making RMSE the most useful when large errors are particularly undesirable.

## Submission Format

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

You should submit a file with two columns: deviceId and winBid. deviceId is the identifier of each separate user in the dataset. winBid is a numerical value, representing the bid that would have won that auction.

The file should contain a header and have the following format:
```
deviceId,winBid
12345abcde,1.051
```