Continuing with the Filthy Money Forecasting personal finance app scenario first described in chapter 2 and relating to previous chapters' exercises, try these: 1. Suppose that your preliminary analyses and descriptive statistics from the previous chapter lead you to believe that you can probably generate some reliable forecasts for active users with financial accounts that have many transactions, but you don't think you can do the same for users and accounts with relatively few transactions. Translate this finding into the "What is possible? What is valuable? What is efficient?" framework for adjusting goals.