Question

a scatter plot shows the relationship between the number of absences and the gpa (on a 4 - point scale) for a large number of high school students.
if the point labeled a is removed, which of the following statements would be true?
a) the slope of the least - squares regression line would decrease and the strength of the association would increase.
b) the slope of the least - squares regression line would decrease and the strength of the association would decrease.
c) the slope of the least - squares regression line would increase and the strength of the association would remain the same.
d) the slope of the least - squares regression line would increase and the strength of the association would increase.
e) the slope of the least - squares regression line would increase and the strength of the association would decrease.

Explanation:

Step1: Analyze the slope

Point A is below the regression line. Removing it, the regression line will be steeper (slope increases) as it was pulling the line down.

Step2: Analyze the strength of association

Since point A is far from the regression line compared to other points, removing it makes the data more clustered around the new regression line. So the strength of the association (how well the data fits the line) increases.

Answer:

D. The slope of the least - squares regression line would increase and the strength of the association would increase.