i have runtime error '6' overflow when i execute following code

Question

If (k > 1) Then
    Dim n3 As Integer, sum3 As Integer
    Text9.Text = Left(Data, k - 1)
    arr3(count3) = Val(Text9.Text) 'Abs(Val(Text9.Text) - WZero) * ktw
    
    For n3 = 0 To count3 Step 1
        sum3 = sum3 + arr3(n3)
    Next
    
    count3 = count3 + 1
    Weight = Abs((sum3 / count3) - WZero) * ktw
    NTGraph1.PlotY Weight, 0
    Text1.Text = Str(Weight)
    
    Select Case (Val(Combo1.Text))
        Case (1)
        MDI.Weight1 = Weight
        Case (2)
        MDI.Weight2 = Weight
        Case (3)
        MDI.Weight3 = Weight
        Case (4)
        MDI.Weight4 = Weight
    End Select
End If