By visual inspection, determine the best-fitting regression model for the data plot below. a. quadratic b. linear c. no pattern d. exponential

The first thing you should do is observe the behavior of the graph.
 It is not linear because the rate of change is not constant.
 It is not exponential because the rate of change does not grow or decrease rapidly.
 For this case the best regression model is a model of the form:
 
 Where,
 a <0: This is because we have a parabola that opens downwards.
 Therefore, the best regression model is quadratic.
 
 By visual inspection, the best-fitting regression model for the data plot is:
 A. Quadratic