why does this code not input a formula into cells
e5 to end of data

Range("D6").Select
Selection.End(xlDown).Select
ActiveCell.Offset(0, 1).Range("A1").Select
Do Until Range("E5").Select
ActiveCell.FormulaR1C1 = "=R2C8/(RC[-2]-RC[-4])"
ActiveCell.Offset(-1, 0).Range("a1").Select
Loop