Here, we would like to discuss the use of line charts. Line charts are a widely used type of chart and are very easy to draw. To construct this chart, the points on the scale of the graph are plotted and then the adjacent points are connected forming a continuous line. The line may be a slope or a step, depending on the type of the data and the purpose of the chart.
Line charts contain more data in a compact space than do the other types of charts.
They should be used when a large number of points are to be plotted, when several series are being compared, or when emphasis is on movement and not on actual amounts. Actual numbers or rates can be charted to provide a running total or average. Multiple lines can be plotted to provide comparison and trends of two data values over the same time period. However, it is not recommended to plot more than four or five lines on a chart, especially if the different data points for the lines are close in value. Excessive range minimizes differences in the data and wastes space.