Weighted average - time spent

[ClauP]

I have a question on weighted average.
I have xx tasks, divided in xx categories. But the time spent is always diferent (5m, 4m59, 5m05, 4m48, etc.), so I’m not able to group them in quantities for each category.

In my example, the "wanted information" is a normal average, but I want to find the weighted average for the time spent in each category, for the different intervals (as days, weeks or months).

Can anyone help me?
Thanks

 

[Swapnil]

Can you please check.... I have populated the formula which can give you weighted average.

Please confirm whether this meets your expectation.

 

[ClauP]

Uau!

I think this is it. Thank you so much for your help