You can use a pivot table...

or

if you list the unique names somewhere on the sheet... you can use formula:

=Sumif($A$1:$A$100,X1,$B$1:$B$100)/Countif($A$1:$A$100,X1)

where A1:B100 contains your original data and X1 contains one of the unique names... then you would copy down the formula.

Note: adjust ranges and references to suit.