Calculating Xbar in Beast Mode
I am trying to create a control chart and need to start by calculating the Xbar.
In this particular dataset, I have multiple inventory transactions that have occurred during a "subgroup" = one day/week. The Xbar calculation = the sum of the transactions during the subgroup period divided by the # transactions, by inventory class.
Nov 1.; Inventory Class1 transactions: 1200+1400+1000+800
Calculation : 4400/4 = 1100
Nov 2. ; Inventory Class1 transactions: 1000+700+1300
Calculation: 3000/3 = 1000
Nov 3.; Inventory Class1 transactions: 1200+500+500+1000
Calculation: 3200/4 = 800
The points I would want to plot on my chart would be 1100, 1000 and 800 for Inventory Class1.
What's the best way to go about accomplishing this?