Everything needed is at the bottom of the first page.
First use the net present worth analysis to determine which alternative, if any, is the most economically favorably. Then look at the means and variations. You can use standard deviations, standard error, confidence level, etc. If you remember enough statistics. You can plot a graphs (Control charts) showing the actual measurements compared to the mean gain a qualitative understanding of the variation. Either way, consider the cost and performance, which alternative would you select, and why? (one paragraph each)