averaging a column based on criteria andputting result in new worksheet

it's not perfect, but functional

Sub macro1()
'100 possible glassgroups
Dim classgroup(100)
Dim item(100)
Dim count(100)
'read in all unique classgroups
'header cell of classgroup column named classgroup
'header cell of itemsordered column named itemsordered
firstrow = Range("classgroup").Row + 1
lastrow = Range("classgroup").End(xlDown).Row
classcolumn = Range("classgroup").Column
itemcolumn = Range("itemsordered").Column
Sheets("Data").Activate
j = 1
For i = firstrow To lastrow
For k = 1 To j
If Cells(i, classcolumn).Value = classgroup(k) Then GoTo nexti _
Else classgroup(j) = Cells(i, classcolumn).Value
If i < lastrow Then j = j + 1
If i = lastrow Then GoTo done
GoTo nexti
Next k
nexti:
Next i
done:
'sum up items for each classgroup
For l = 1 To j
For i = firstrow To lastrow
If Cells(i, classcolumn) = classgroup(l) Then item(l) = item(l) _
+ Cells(i, itemcolumn)
Next i
Next l
'count occurances of each classgroup
For l = 1 To j
For i = firstrow To lastrow
If Cells(i, classcolumn) = classgroup(l) Then count(l) = count(l) _
+ 1
Next i
Next l
Sheets("Report").Activate
' place classgroups in column A and average of items ordered in column B
' starting in row 2
For l = 1 To j
Cells(l + 1, 1).Value = classgroup(l)
If count(l) <> 0 Then _
Cells(l + 1, 2).Value = item(l) / count(l)
Next l
End Sub

a little better and will exclude blanks from the averages

Sub macro1()
Sheets("Data").Activate
'100 possible glassgroups
Dim classgroup(100)
'header cell of classgroup column named classgroup
'header cell of itemsordered column named itemsordered
firstrow = Range("classgroup").Row + 1
lastrow = Range("classgroup").End(xlDown).Row
classcolumn = Range("classgroup").Column
itemcolumn = Range("itemsordered").Column
Range(Cells(firstrow, itemcolumn), _
Cells(lastrow, itemcolumn)).Name = "itemlist"
Range(Cells(firstrow, classcolumn), _
Cells(lastrow, classcolumn)).Name = "classlist"
Sheets("Data").Activate
'read in all unique classgroups
j = 1
For i = firstrow To lastrow
For k = 1 To j
If Cells(i, classcolumn).Value = classgroup(k) Then GoTo nexti _
Else classgroup(j) = Cells(i, classcolumn).Value
If i < lastrow Then j = j + 1
If i = lastrow Then GoTo done
GoTo nexti
Next k
nexti:
Next i
done:
skip:
Sheets("Report").Activate
For l = 1 To j
Cells(l + 1, 1).Value = classgroup(l)
Cells(l + 1, 2).Formula = _
"=sumproduct((classlist=Report!RC[-1])*(itemlist))/sumproduct((classlist=Report!RC[-1])*(itemlist<>""""))"
Next l
End Sub

I think this works better - sorry about that I did not test other one enough. You may also want to add something to clear the Report sheet before you paste the new info.

Sub macro1()
Sheets("Data").Activate
'100 possible glassgroups
Dim classgroup(100)
'header cell of classgroup column named classgroup
'header cell of itemsordered column named itemsordered
firstrow = Range("classgroup").Row + 1
lastrow = Range("classgroup").End(xlDown).Row
classcolumn = Range("classgroup").Column
itemcolumn = Range("itemsordered").Column
Range(Cells(firstrow, itemcolumn), _
Cells(lastrow, itemcolumn)).Name = "itemlist"
Range(Cells(firstrow, classcolumn), _
Cells(lastrow, classcolumn)).Name = "classlist"
Sheets("Data").Activate
'read in all unique classgroups
j = 1
For i = firstrow To lastrow
For k = 1 To j
If Cells(i, classcolumn).Value = classgroup(k) Then GoTo nexti
Next k
classgroup(j) = Cells(i, classcolumn).Value
j = j + 1
nexti:
Next i
done:
j = j - 1
Sheets("Report").Activate
For l = 1 To j
Cells(l + 1, 1).Value = classgroup(l)
Cells(l + 1, 2).Formula = _
"=sumproduct((classlist=Report!RC[-1])*(itemlist))/sumproduct((classlist=Report!RC[-1])*(itemlist<>""""))"
Next l
End Sub