How to complete empty fields with average values

[#1]

Hi for All! Could anybody support me please?

1)  I want to find the value into [Payment Plan] within the Transformer Script process when:

     [Fiscal Week] = 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52.

     [Period Week] = 4

2) To complete the empty fields with average values between diferents intervals. For instance:

When to find values into [Payment Plan] on [Fiscal Week]=16 and [Periodo Week]=4; then SUM those values and after that take the average  (divide by 28) and fill with this value each the following 28 days of [Fiscal Date] and to insert inside [Payment Plan] empty fields... until find the next value into [Payment Plan] and  [Fiscal Week]=20 and [Periodo Week]=4 and do the same until find the next value,... so on and so forth...

I thought to apply INTERVALMATCH function but i read to need 2 tables but I have all in one.

If anybody could guide me, please let me know. I appreciate so much!

Thanks for advance, All the best

P.D.: I have all of these fields into mine Table.

[#2]

You can break the tables into 2 tables and apply IntervalMatch. You can calculate the seconds table have averages and do the intervalmatch.

Also you can use While and  IterNO() function to generate the loops with in the keys.