Answer:
Not very. The closer the value of your correlation coefficient is to 0, the weaker the correlation. Here, our correlation coefficient is only 0.089 away from 0 - in other words, there's not much correlation in the number of plagiarized assignments and the score on their final exam. If you were to plot this data on a graph, it would look like a pretty sparse "blob" of dots, where with a higher correlation, we'd expect a tighter grouping around the line of best fit. See the illustration for an example of strong/weak correlation in both negative and positive directions.
The sign of our correlation coefficient is negative, which means that generally, for what weak correlation we have, the score on the final exam goes down as the number of copied assignments go up. This makes sense - the more assignments you copy, the less you tend to retain.