Is a scatter plot the same as a line graph?

A scatter plot is a plot of paired (x,y) data with a horizontal x axis and a vertical y-axis. (definition as given in Elementary Statistics by Triola). Textbooks may have different definitions. If one variable is considered an independent variable, then generally it is the x value. This is particularly important if there is a relationship between the two variables, in that knowing the x value helps predict the y value. A best fit line can be drawn through the points.

A line graph in general connects points on a graph. The x-axis may not be a numerical value or it may not be equal spaced increments. For example, suppose I did surveys in years 2001, 2002 and 2009, counting how many accidents there were in a particular intersection. A line graph would show three years, 2001, 2002 and 2009, as equal spaced intervals on the x-axis.

The above definition is consistent with plots made in Excel. I note that some textbooks may consider a line graph as any plot that contains lines connecting the data.

See related links. You can find many good examples of graphical displays of data on the internet.