題組內容

4. Marks obtained by 12 students in first pre-final examination (x) and second pre-final examination (y) are given below.
x: 12.0, 14.0, 9.5, 10.5, 8.0, 11.5, 10.0, 14.0, 8.0, 9.5, 11.0, 12.0
y: 11.5, 13.5, 12.0, 14.0, 7.0, 14.0, 8.0, 12.5, 6.5, 10.0, 9.0, 12.0
where , , , , .


(a) Calculate correlation coefficient between x and y. (5 points)