How to statistically compare a change between two curves with the change between two other curves.
I have two stores. each store sends a notification when they make a sale. The notification specifies how many of a specific item were sold.Some days no notifications, other days several. For example store A send 45 notifications of total 78 items for January 2019, compared to 40 notifications of total 68 items for January 2020.I receive a monthly report of the notifications. I created a column wit...