I completed the exercise, getting my results to match the "Final State"... but I disagree with the removal of duplicate Customer_ID 787.
We don't have enough information to know which record is the true/clean data. One showed 100, the other 86; without the "why" for removing this duplicate, we don't know if our combined results are correct.
This duplicate could have 1 of 3 different "true" record results:
1. truly was duplicate and should be 86...good Final State
2. truly was duplicate and should be 100...our Final State just shorted a customer 14 sales
3. erroneous duplicate entry, could have been two separate total sales entries that should have been summed to get 186...our Final State just shorted a customer 100 sales
