Variable data set in Average formula

[Filip88]

Hello,

i have range of cells (column A). I want to count average from data from Column A in column B, but the range of average should be able to change based on my input in cell C2. It means when i input number 3 in C2, it should count average of 3 cells from column A, if i input 10 in C2, it should count average of 10 cells etc. Based on my input in cell C1 the formulas in column B would use different data set to be processed.

Basically column A has data, column B has formulas to be changed based on input of cell C2

Is somehow possible to do that in excel formulas? Or it is inevitable to use VBA?

I would appreciate if somebody has any advice. I have attached excel sheet.

Thank you

Filip