The following data were obtained in a study of the relationshipbetween diastolic blood pressure (Y) and age (X) for boys 5 to 13years old.
X | 5 | 8 | 11 | 7 | 13 | 12 | 12 | 6 |
Y | 63 | 67 | 74 | 64 | 75 | 69 | 90 | 60 |
Fit a simple linear regression model to the data and plot theresiduals against the ï¬tted values.
Omit case 7 and reï¬t the model. Plot the residuals versus theï¬tted values and compare to what you got in (a).
Using the ï¬tted model from (b), obtain a 99% prediction intervalfor a new Y observation at X = 12. Does observation y7fall outside this prediction interval? What is the signiï¬cance ofthis?
