Invalid Qualifier error with Slope function - vba

Question

New to VBA and got this qualifier error for a code that's supposed to calculate the slope of two arrays and place it in a column with the given address.
Beats me so far, so it'd be nice to have some help! The sizes of the arrays are matching.
The compile error is given at the .Slope within the TargetSheet.Cells(n, (MyRange.Columns.Count) + 1).Value = Application.WorksheetFunction.Slope(TargetSheet.Range(TargetSheet.Cells(n, 5), TargetSheet.Cells(n, MyRange.Columns.Count)), TargetSheet.Range(TargetSheet.Cells(1, 5), TargetSheet.Cells(1, MyRange.Columns.Count))).Value
Dim n As Long
Dim MyRange As Range
Set MyRange = ActiveSheet.UsedRange
Dim TargetSheet As Worksheet, SourceSheet As Worksheet
Dim TargetBook As Workbook
Set TargetBook = Application.ActiveWorkbook
Set TargetSheet = Application.ActiveSheet
For n = 3 To MyRange.Rows.Count
TargetSheet.Cells(n, (MyRange.Columns.Count) + 1).Value = Application.WorksheetFunction.Slope(TargetSheet.Range(TargetSheet.Cells(n, 5), TargetSheet.Cells(n, MyRange.Columns.Count)), TargetSheet.Range(TargetSheet.Cells(1, 5), TargetSheet.Cells(1, MyRange.Columns.Count))).Value
Next n
End With
End Sub
A version before this one (can't undo till that point :/) was working up till a point where it stopped and gave the qualifier error. I used Excel's SLOPE function on the data set and compared alongside: it was giving this error at a #DIV/0 result (but the VBA didn't show that).

Answer 1

As stated, removing .Value from the slope call allows it to pass the compiler.
Otherwise, it seems to work.
This input ...
Provided this output ...
Using this code (slightly modified to get the correct columns) ...
Sub main()
Dim n As Long
Dim MyRange As Range
Set MyRange = ActiveSheet.UsedRange
Dim TargetSheet As Worksheet, SourceSheet As Worksheet
Dim TargetBook As Workbook
Set TargetBook = Application.ActiveWorkbook
Set TargetSheet = Application.ActiveSheet
For n = 2 To MyRange.Rows.Count
TargetSheet.Cells(n, (MyRange.Columns.Count) + 1).Value = _
Application.WorksheetFunction.Slope(TargetSheet.Range(TargetSheet.Cells(n, 1), TargetSheet.Cells(n, MyRange.Columns.Count)), _
TargetSheet.Range(TargetSheet.Cells(1, 1), TargetSheet.Cells(1, MyRange.Columns.Count)))
Next n
End Sub
Below is revised code to capture case when only 1 Y value is present to avoid divide by zero. This assumes that row 1 in the worksheet will have nothing to the right of the headers.
Option Explicit
Sub main()
Dim n As Long
Dim MyRange As Range
Dim nRows As Long, nCols As Long, ColCount As Long
Set MyRange = ActiveSheet.UsedRange
Dim TargetSheet As Worksheet, SourceSheet As Worksheet
Dim TargetBook As Workbook
Set TargetBook = Application.ActiveWorkbook
Set TargetSheet = Application.ActiveSheet
nRows = MyRange.Rows.Count
nCols = MyRange.Rows(1).End(xlToRight)
For n = 2 To nRows
ColCount = Application.CountIf(TargetSheet.Range(TargetSheet.Cells(n, 1), Sheet1.Cells(n, nCols)), """<>""""""")
If ColCount > 1 Then
TargetSheet.Cells(n, (MyRange.Columns.Count) + 1).Value = _
Application.Slope(TargetSheet.Range(TargetSheet.Cells(n, 1), TargetSheet.Cells(n, MyRange.Columns.Count)), _
TargetSheet.Range(TargetSheet.Cells(1, 1), TargetSheet.Cells(1, MyRange.Columns.Count)))
End If
Next n
End Sub

Answer 2

Thanks #OldUgly! Managed to fix the error. Reason for VBA: automate for multiple data sheets in the same format with varying no. of columns and rows.
WorksheetFunction.Slope doesn't like it when there's only one data point and the rest of one array is empty.
I created another loop to count non-empty cells within the For loop for each row. If the no. of non-empty cells is < 2 for a particular row, the output would be "Insufficient Data".
If not, then the slope value would be calculated.
Another, less painstaking way to get around this issue is to simply use On Error Resume Next for this specific case.
Dim n As Long, o As Range, CurrentRow As Range, NonEmptyCellCountRow As Integer
For n = 3 To MyRange.Rows.Count `Within each row, counting non-empty cells
Set CurrentRow = TargetSheet.Range(TargetSheet.Cells(n, 5), TargetSheet.Cells(n, MyRange.Columns.Count))
NonEmptyCellCountRow = 0
For Each o In CurrentRow
If o.Value <> "" Then NonEmptyCellCountRow = NonEmptyCellCountRow + 1
Next o
If NonEmptyCellCountRow < 2 Then _
TargetSheet.Cells(n, (MyRange.Columns.Count) + 1) = "Insufficient Data"
Else
TargetSheet.Cells(n, (MyRange.Columns.Count) + 1) = Application.WorksheetFunction.Slope(TargetSheet.Range(TargetSheet.Cells(n, 5), TargetSheet.Cells(n, MyRange.Columns.Count)), TargetSheet.Range(TargetSheet.Cells(1, 5), TargetSheet.Cells(1, MyRange.Columns.Count)))
End If
Next n