Filter Selection Data

Hi everyone,

Imagine that you have a lot of data, and you want to categorize them , I mean, according their value or other criteria I want to group them...

1.236 Group A
12.35 Group B
1253.5 Group B
123.56 Group A

Now I'm trying to use a excel filter to choose only de 'A' values or the 'B' values. The thing is, when I'm trying to calculate an average using the excel filter on a certain group and press keys 'ctrl+shift+arrow' the calculation is performed with every values listed even those that are 'hidden' (in other groups)...

The question is : "how can I calculate the average of a only group filtered with excel filters? without selecting them manually..."

Thank you a lot!

Thank you so much both of you!!!