Question

Using a sample of 60 undergraduates, Dr. Hotchkins discovers a negative correlation between stress and emotional well-being. While looking at a scatterplot of the data, Dr. Hotchkins realizes there are 4 outliers in the data, all for individuals with extremely high scores on stress and extremely high scores on well-being. What is the effect of these outliers on the correlation

Answer 1

Answer and explanation:

A negative correlation means a relationship between two variables whereby each variable affects the other such that an increase in one variable means a decrease in the other and vice versa. This is the situation with the correlation graph/scatter plot of Dr. Hotchkins: An increase in stress would cause a decrease in emotional well being and vice versa

An Outlier is a data point on the scatter plot that does not fall into the pattern of the correlation graph. From the above, 4 points are outliers: extremely high points on stress and emotional well being. These points would affect (increase or decrease) the correlation coefficient depending on where they fall in the pattern. In this case there are 4 outliers out of 60 data points and we know that the more outliers there are the more effect they have on the correlation coefficient and vice versa(also depending on where the outlier is on the scatter plot)