All solutions here are SUGGESTED. Mr. Teng will hold no liability for any errors. Comments are entirely personal opinions.

(i)

(ii)

Using Graphing Calculator, .

Since is close to 1, there is a strong negative correlation between the number of hours spent travelling to and fro work and the number of hours spent watch television.

(iii)

Using Graphing Calculator, equation of regression line of is

(iv)

When hours

The estimate is not reliable since is outside the range of sample data.

### KS Comments

Students must check what they key in very carefully. And for the drawing of regression line, students must learn how to store them properly so as to draw as precisely as possible.