I am working on some data, more specifically some predictions of some outcomes. The predictions vary on the continuous scale, between $-3$ and $3$. They can for example be:
$x_1=-2.4, x_2=-2.1, x_3=1.4, x_4=0.4, \cdots, x_n=-1.2$
Now, for each prediction, I also have the corresponding results,
$y_1, y_2, \cdots , y_n$,
which also are continuous.
How can I check if my predictions are good or not? I do not have any knowledge whatsoever on how the predictions are made, thus cannot create any confidence interval around the predictions.