Suppose you work for a company that produces cocktail kits to make cocktails at home (I'm partial to Tom Collins these days...).Sales have soared since March 2020.In a recent meeting, the marketing group kept patting themselves on the back, attributed the sales growth to their recent marketing campaign released around March 2020.Indeed, they provide "evidence" of this causal story in the form of a table showing monthly sales growth together with growth in monthly advertising expenditures associated with the marketing campaign.What is wrong with this "evidence," and how would output from a multiple regression provide better insight into any causal relationship between sales growth and advertising?