Binaryworld - ArrayAvg - The average of an array of any type ... [ VB -> Arrays ]

' The average of an array of any type
'
' FIRST and LAST indicate which portion of the array
' should be considered; they default to the first
' and last element, respectively
' if IGNOREEMPTY argument is True or omitted,
' Empty values aren't accounted for

Function ArrayAvg(arr As Variant, Optional First As Variant, _
  Optional Last As Variant, Optional IgnoreEmpty As Boolean = True) As Variant
  Dim index As Long
  Dim sum As Variant
  Dim count As Long

  If IsMissing(First) Then First = LBound(arr)
  If IsMissing(Last) Then Last = UBound(arr)

  ' if arr isn't an array, the following statement raises an error
  For index = First To Last
    If IgnoreEmpty = False Or Not IsEmpty(arr(index)) Then
      sum = sum + arr(index)
      count = count + 1
    End If
  Next

  ' return the average
  ArrayAvg = sum / count

End Function