Analyzing expenses with conditional aggregation

In the following exercises, you'll be working as a financial analyst in the accounting department of a regional carpet shop. The Head of Accounting has been informed that some of the traveling salespeople may have been misusing company expenses, and it's your job to dig into the data of the expense reports and determine if this appears true.

You've explored and cleaned the expense report data so it's in a format that can now be analyzed to yield valid results. Time for the analysis!