Exercise 6.2 & 6.3 typos

[TomSteeples]

6.2 - Date in screenshot is wrong. I inadvertently used the MIN rather than MAX date.
6.3 - Alias in the slides for 'in inventory' is wrong. This should just be 'inventory'

[TomSteeples]

6.2 - Avg Revenue & Items Sold should be to 2 decimal places, not 1