Statistics

A soda distributor claims that a new display, featuring Lebron James will increase product sales in supermarkets by an average of 50 cases in a week. For a random sample of twenty supermarkets, the average sales increase was 41.3 cases, and varied across supermarkets by about 12.2 cases.

Most imporatantly, what managerial conclusion can you draw from this data?

I am supposed to use one or more of the following techniques (and we are instructed to always use 95% confidence level, unless the problem states otherwise):
-Confidence intervals and hypothesis testing -Decision trees (and their use in solving managerial problems),
-Critical fractile analysis (and its use in determining optimal demand levels),
-Analysis of variance/ANOVA (and its use in understanding differences between group means),
-Chi-square (cross tabs/contingency table) analysis (and its use in determining differences between group proportions),
-Regression, single and multiple (and its use in understanding relationships between dependent and independent (explanatory) variables), and
-Optimization modeling (and its use in determining the best solution given a set of constraint).

I do not know how to do this. Help!!