Excel auto weekly average

Hi beautiful excel community.
Hope you are all doing good.

I want excel to make automatic weekly averages when weekend (Friday) occur.
Can anyone help me with that?
Attaching sample sheet for your reference.
For example; In 1st week there were 3 workdays, in 2nd week full week was working day and in 3rd week only three working days.
1ST WEEK AVERAGE SHOULD BE: 2183.33
2ND WEEK AVERAGE SHOULD BE: 4660.6
3RD WEEK AVERAGE SHOULD BE: 4836.5

Uppers are the manual calculation by entering formula. However, I want that Excel should automatic find that specific rage is a week.
Like this is 3 days week so Excel auto add all 3 values and divide / 3 at its own.


Waiting for your valuable replies. Work Sheet.xlsx