If the point in the upper right corner of this scatterplot is removed from the data set, then what will happen to the slope of the line of best fit (b) and to the correlation (r)?
A) both will decrease.
B) both will remain the same.
C) both will increase.
D) b will decrease, and r will increase.
E) b will increase, and r will decrease.

Question

If the point in the upper right corner of this scatterplot is removed from the data set, then what will happen to the slope of the line of best fit (b) and to the correlation (r)? 
A) both will decrease. 
B) both will remain the same. 
C) both will increase. 
D) b will decrease, and r will increase. 
E) b will increase, and r will decrease.

Quizplus · Accepted Answer

The point in the upper right corner is an outlier and has a strong influence on the slope of the line of best fit. Therefore, removing this point will reduce the magnitude of the slope (b will decrease). Additionally, since the outlier was positively correlated with the rest of the data, removing it will decrease the correlation between the remaining data points (r will increase). Therefore, the correct answer is D.

If the Point in the Upper Right Corner of This