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.
Can a circle graph be used to display data from a histogram? What type of data can line graphs display? Line graphs are used to display data to show how one variable (the  Responding variable) changes in response to another variable (the  Manipulated variable). Making the world better, one answer at a time.