What Jason is asked to do is to find a correlation or dependence between random variables, the idea is to know what could be causing the increase of sales, for that Jason has the amount sell and a lot of other variables. One possible result of the experiment would be a relationship between the diversity of products (how many different items are in the store) and the sellings. The conclusion of Jason could be that the sellings have increased since the induction of a diversity policy two years ago.
Note: Analysing data is a long and difficult process, and the answer describe here is just one way to do it and it doesn't apply for all cases.
