When it comes to Formulas I am so lost. I am looking for the following formula.

I am working with the following Sum formulas

=SUM(E3:E20)/7

I have information to write in E3 to E20. (Numbers) some cells will be blank.

I need the following formula:

Look in E3 to E20 and calculate the total Then

Calculate the total amount of cells populated then keep it in bank

Now take the first total then divided it by the total amount of cells (populated) while skipping the blank cells

Example:

E3: 2

E4: 4

E5:

E6: 7

E7: 2

Total: 15

There is 4 numbers from E3 to E7 therefore divide this total number by 4 = 3.75

3.75 Should go in E9.

How in the H can I do this...

Please Help Ièm going nuts