Table 4E.11 contains the data from a patient satisfaction survey for a group of 25 randomly selected patients at a hospital. In addition to satisfaction, data were collected on patient age and an index that measured the severity of illness.

(a) Fit a linear regression model relating satisfaction to patient age.
(b) Test for significance of regression.
(c) What portion of the total variability is accounted for by the regressor variable age?

TABLE 4E. 11 Pationt Satisfaction Data Observation Age Severity (r) Satisfaction () 68 46 35 59 43 58 60 65 74 26 27 42 75 53 38 12 15 48 61 58 62 38 70 59 52 83 75 25 49