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.
Graphs in Economics. Graphs are often used in economics to display concepts in a visual form. Economics at the basic level makes heavy use of graphs, so it's important to understand how to read them. In economics graphs are often used to show the relationship between two concepts, such as, price and quantity. Most graphs used in economics only work with the upper right corner or the northeast quadrant. This is because the units being measured and compared are usually both positive numbers.