In a statistics subject, a teacher wanted to study the relationship between the number of times for a student absent from a class (x) and their corresponding test scores (y). A random sample of 5 students was selected in the subject. The data are summarized in the following table.

No. of Times of Absences (x) 3 +U2 +UTest Score (y) 22 39

1 +U48

4 +U24

2 +U42

(3 marks) (4 marks) (3 marks)

1. (a)Find the equation of the least-squares liney=a+bx.
2. (b)Calculate the correlation coefficient and interpret its meaning.
3. (c)Calculate the coefficient of determination and interpret its meaning.