- What is the purpose of regression equation? Answer: The purpose of regression equation is to help you identify the relationship of between a dependent variable and one or more independent variables. The most common form of regression is the linear regression in which a researcher finds a line that most closely fit the data according to a specific mathematical principle.
- What does the 3 represent in the model y = 5 + 3x? Answer: It represents the slope. Obviously, the model shown in this problem is linear because it is the form of y = mx + b if you recall. The number that is attached to x is called the slope. It describes the steepness and direction of a line. Don't get confuse if somebody tells you a different description because slope comes in different names like, rate of change, derivative, constant of proportionality, etc..
- What does the 5 represent in this model? Answer: It represent the y-intercept which is the y-coordinate of the point of intersection of y-axis and the linear model itself. It is also defined as the value of y if x is zero.
- If the model represents the relationship between the number of new cars sold and the number of sales people on duty, how can this model be interpreted? Answer: Identify the dependent variable (y) and the independent variable (x). Here, we can say that the number of new cars sold (y) depends on the number of sales people on duty (x). Therefore, we can interpret that whenever there are 3 cars sold, they put an additional sales person to work, and they started selling cars with 5 sales people on duty.
