The effect of an outlier. Refer to Exercise 4.41. Add a ninth student whose scores on the second test and final exam would lead you to classify the additional data point as an outlier. Recalculate the correlation with this additional case and summarize the effect it has on the value of the correlation.
Exercise 4.41
Second test and final exam. In Exercise 4.25 you looked at the relationship between the score on the second test and the score on the final exam in an elementary statistics course. Here are the data:
(a) Find the correlation between these two variables.
(b) Do you think that the correlation between the first test and the final exam should be higher than, approximately equal to, or lower than the correlation between the second test and the final exam? Give a reason for your answer.