Tea Tree Oil is used commercially in many products including shampoos, body lotions and toiletries, but there is no legislation requiring manufacturers to state the concentration of tea tree oil in these products.
Line Graphs. One of the most common graphs you will encounter is a line graph. Line graphs simply use a line to connect the data points that you plot. They are most useful for showing trends, and for identifying whether two variables relate to (or correlate with) one another.
Seven of the most common graphs in statistics are listed below: 1  Pareto Diagram or Bar Graph - A bar graph contains a bar for each category of a set of qualitative data. 2  Pie Chart or Circle Graph - A pie chart displays qualitative data in the form of a pie. 3  Histogram - A histogram in another kind of graph that uses bars in its display.