Marble experiment

We thought about rolling a marble down a slope. We predicted that the steeper the slope, the faster the marble would roll and the further it would go. We did an experiment to test our prediction and see if we were right.
We rolled a marble down a slope and timed how long it took to cross a chalk line on the floor. Then when the marble stopped rolling, we measured how far it had rolled.
We wrote our results into a table:

We found out that our prediction was correct, until the steepest slope. We thought about why the steepest slope was slower. We thought that it was because when the marble hit the floor it bounced (the floor pushed back against the marble) and slowed the marble down.