At a bank customers are applying for a loan and then the customer gets a loan-offer which they can choose to accept or not. This bank has been running for 11 weeks and by coincidence a developer saw that odd applications-ids in average generate higher accepted amounts than even application-ids, every week. Application-id is just an incrementing number in the database, so has nothing to do with real world. There is no reason for why this would happen, so the question is, how likely is this to happen by chance? Someone said this can happen because splitting on odd/even application-id is not purely random. But isn't it random enough?
In the image you see the data:
- Column 1: week
- Column 2: group (even/odd application-id)
- Column 3: number of applications
- Column 4: number of accepted offers
- Column 5: sum of accepted amount
- Column 6: a flag if the accepted amount is bigger for odd application-ids (which it is for all 11 weeks)
- Column 7: A calculation by how much the accepted amount is bigger for odd application-ids.