A random sample of patients who attended a clinic was selected. The age of the patient (years) and the number of days since the last visit were collected and are displayed in the figure below. The least-squares regression line for predicting number of days since the last visit from the age of the patient is y = 600.081 - 8.694x. The slope of this line is
A) 600.081.
B) 8.694.
C) -8.694.
D) 600.081 - 8.694 = 591.387.

Question

A random sample of patients who attended a clinic was selected. The age of the patient (years) and the number of days since the last visit were collected and are displayed in the figure below. The least-squares regression line for predicting number of days since the last visit from the age of the patient is y = 600.081 - 8.694x.  The slope of this line is
A) 600.081. 
B) 8.694. 
C) -8.694. 
D) 600.081 - 8.694 = 591.387.

Quizplus · Accepted Answer

The slope of the least-squares regression line represents the rate of change of the response variable (in this case, number of days since last visit) per unit increase in the predictor variable (in this case, age). Therefore, the slope is -8.694, indicating that for each additional year of age, the predicted number of days since the last visit decreases by approximately 8.694 days.

A Random Sample of Patients Who Attended a Clinic Was