Help with formula to calculate average percentage for each consecutive cell based on the number of cells

[Sparker65]

Hi, this is my first time post and I need help with a formula to calculate the average percentage for each cell including the previous cell. For example, cell I2(Apr-18) contains a percentage, I would like to add that percentage to cell J2(May-18) and find the average, and for cell K2(Jun-18), I would like to add cells I2, J2, and K2 and find the average. The desired results are in columns 1-3. I have 12 cells in each row. I can do it manually but I would like a formula. See sample data below.

Thanks!

[TABLE="width: 1220"]
<colgroup><col><col><col><col><col><col><col><col><col><col><col span="2"><col span="3"></colgroup><tbody>[TR]
[TD]Apr-18[/TD]
[TD]May-18[/TD]
[TD]Jun-18[/TD]
[TD]Jul-18[/TD]
[TD]Aug-18[/TD]
[TD]Sep-18[/TD]
[TD]Oct-18[/TD]
[TD]Nov-18[/TD]
[TD]Dec-18[/TD]
[TD]Jan-19[/TD]
[TD]Feb-19[/TD]
[TD]Mar-19[/TD]
[TD]Column1[/TD]
[TD]Column2[/TD]
[TD]Column3[/TD]
[/TR]
[TR]
[TD]95.65%[/TD]
[TD]97.83%[/TD]
[TD]97.83%[/TD]
[TD]97.83%[/TD]
[TD]89.13%[/TD]
[TD]91.30%[/TD]
[TD]89.13%[/TD]
[TD]86.96%[/TD]
[TD]93.48%[/TD]
[TD]97.8%[/TD]
[TD]93.5%[/TD]
[TD]91.3%[/TD]
[TD]95.65%[/TD]
[TD]96.74%[/TD]
[TD]97.10%[/TD]
[/TR]
</tbody>[/TABLE]

 

[JoeMo]

If the 1st percentage is in I2 then in cell U2: =AVERAGE($I2:I2)
and copy to the right.

 

[Sparker65]

Hi Joe,

Thanks so much! I forgot the $ in the formula. I really appreciate the assistance.