Scatter charts are common in scientific, medical, and statistical spreadsheets. They're particularly useful when you don't want to connect every dot with a straight line. Instead, scatter charts let you use a smooth "best fit" trendline, or omit the line altogether. If you plot multiple series, the chart uses a different symbol (like squares, triangles, and circles) for each series, ensuring that you can tell the difference between the points.
Scatter chart subtypes overview:
Scatter with Only Markers
This scatter chart uses data markers to show where each value falls. It adds no lines.
Scatter with Smooth Lines and Markers
This scatter chart adds a smooth line that connects all the data points. However, the points are connected in the order they occur in the chart, which isn't necessarily the correct order. You're better off adding a trendline to your chart.
Scatter with Straight Lines and Markers
This subtype is similar to the scatter chart with smoothed lines, except it draws lines straight from one point to the next. A line chart works like this, and this subtype makes sense only if you have your values in a set order (from lowest to largest or from the earliest date to the latest).
Scatter with Smooth Lines and Scatter with Straight Lines
These subtypes are identical to the scatter with smooth lines and markers and the scatter with straight lines and markers. The only difference is they don't show data markers for each point. Instead, all you see is the line.