Represents the error bars on a chart series. Error bars indicate the degree of uncertainty for chart data. Only series in area, bar, column, line, and scatter groups on a 2-D chart can have error bars. Only series in scatter groups can have x and y error bars. This object isn't a collection. There's no object that represents a single error bar; you either have x error bars or y error bars turned on for all points in a series or you have them turned off.