Step 1

a) It is easy to determine if the regression line slopes upwards, slopes downwards or is horizontal, without having to calculate the slope explicitely.

b) The data should be roughly have a linear pattern (points lie roughly about a line).

a) It is easy to determine if the regression line slopes upwards, slopes downwards or is horizontal, without having to calculate the slope explicitely.

b) The data should be roughly have a linear pattern (points lie roughly about a line).