Filling in an array with data from a range that fall below the average

[seigna]

I am trying to select those values from a one-dimensional range of data that fall below the average. Also, I am trying to count how many of them there are, and finally, to calculate the variance.
This code doesn't seem to be working and I think the problem comes when I populate the array :/

 Function MoyBelow(data As Range) As Variant     
    Dim i As Integer     
    Dim N As Long     
    Redim BelowAvg() As Variant     
    Dim Varian As Double     
    Dim Somcar() As Variant          

    N=WorksheetFunction.Average(data)     
    RendMoy=WorksheetFunction.Average(data)          

        For i=1 To N         
            If data.Cells(i).Value < RendMoy Then             
                BelowAvg(i).Value = data(i).Value         
        End If         
        NB = BelowAvg.Count                  
        
             For j=1 To NB             
                 SumSq= SumSq + (BelowAvg(i) - RendMoy)^2        
             Next i                  
   
             Varian = Somcar/NB     

    End Function