An ice cream vendor would like to predict daily sales of ice cream cones based on the temperature outdoors. Data for a random sample of 8 days are provided in the table below.

Temperature (°C) (x) Daily Sales (Litres) (y)
6 135
8 50
12 125
16 100
18 200
22 150
28 250
28 175
The regression line with "daily sales" as the dependent variable and "temperature" as the independent variable has been calculated as:


You may use the following sums of squares and cross products for the questions below.


What percentage of the variation in daily sales is explained by its linear relationship with temperature?