Interpreting Relationships

A line of best fit is a straight line that best represents the association shown on a scatterplot. It’s often written in y = a + bx form. 

To determine if a relationship is linear or exponential, examine the change in the quantity between successive time periods. If the difference in the quantity is constant, the relationship is linear. If the ratio in the quantity is constant (for instance, 4 times greater than the preceding time period), the relationship is exponential.