As an internal auditor for CRA, Inc., you are assigned to a team working on an ongoing project to identify possible fraud. The project started with time trend analysis of purchase prices of all items in the company. The project was started last year, but because of budget problems, it was delayed until this year. Most of the data mining is complete, but the team is having problems understanding how to continue the approach. Describe the steps in time trend analysis, including correct data prepa