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.
1) Vertical Bar Charts. Vertical bar charts are best for comparing means or percentages between 2 to 7 different groups. As you can see, each bar is separated by blank space. For this reason, the x-axis should be based on a scale that has mutually exclusive categories (like multiple choice, or check box questions).