Cumulative Average Calculation

[johnnyjohn]

I have data as shown below. I am trying to calculate the cumulative average of the volume. So essentially I am trying to create Column F (Cumul Avg Vol) in Qliksense. The cumulative aspect is by increasing Bucket value. 

For example: 

Sub Order 1 and 2 are in the same Bucket (=5) so calculate the average volume of these (7.5).

Sub Order 3 is a larger Bucket value (10), so calculate the average of the volume of Sub Order 1, 2, 3 (5.75). 

Sub Order 4 and 5 have the same larger Bucket value (15) , so calculate the average of all smaller Bucket values, so row 1, 2, 3, 4, 5 (5.83). 

Sub Order 6 has a larger Bucket value (25) , so calculate the average of all smaller Bucket values, so row 1, 2, 3, 4, 5, 6 (6.125). 

by increasing bucket. I.e. if the Bucket for the Sub Order ID is less

[johnnyjohn]

Bump. Any ideas here please? 

[johnnyjohn]

little bump here in case any can help