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.
With the bar graph function, you can use a clustered or stacked bar graph that shows a second number that is identified with the variable. Make sure that the sub-data series is labeled at the top of the third column. Also, ensure that the data is given using the same format, such as dollars or numbers.