In Microsoft Excel, to draw attention to a specific marker in a line chart, drop in a thin line, think of it as a marker.

Grid lines add horizontal and/or vertical lines to your graph that aid in measuring graph values. By default, these grid lines use the color assigned to the "automatic" selection feature, which is ...

One way to assess this fluctuating data is to add a linear trend line to the Excel 2013 graph. This visual element considers all the data and displays the overall direction the values are taking.