The data below show the mean swimming speed (m/s) of basking sharks of various lengths (m).

Length (m)	Speed (m/s)	Predicted speed	Residual
2.5	3
3.5	4.5
5	4.8
5.5	5.2
6	5.5

15. Use your line of best fit to find the predicted swimming speed for each length. Round to the nearest hundredth, and enter the values in the third column of the table.

16. Calculate the residual for each length. Round to the nearest hundredth, and enter the values in the fourth column of the table.

17. Plot the residuals.

18. Based on the residuals, is your regression line a reasonable model for the data? Why or why not?