How do you calculate an average value based on distinct values in another column

[Andrea Thompson]

Hi All,

 

In my data I have mulitple entities, with multiple rows of data, identified by "NUMBER" column. For each entity, I have two MD perforation values, Perforatoin Min and Perforation Max, that I need to use to calculate the average TVD value for all rows that fall between the Perforation Min and Max values on the MD column. I have written this line:

Column Name: TVD_Effective If(([MD]>=[Perforation Min]) and ([MD]