how can i use Excel.ChartLineStyle.dash. I want to change from a solid line to a dash line

dataRange = berechnungsheet.getRange("AG5:AG54");
        var newSeries = chart.series.add("Mittelwert");
        newSeries.setValues(dataRange);
        newSeries.line.style = Excel.ChartLineStyle.dash;

The above code does not deliver a result.