The line of best fit equation is,
[tex]y=0.4x+23.26[/tex]The observed value is what we get from the table.
The predicted value is what we get from using the line of best fit equation.
The residual is Observed - Predicted.
Now,
For number of hours worked = 8,
Observed amount (from table) is 33.50
Predicted amount (using equation) is
[tex]\begin{gathered} y=0.4x+23.26 \\ y=0.4(8)+23.26 \\ y=26.46 \end{gathered}[/tex]Residual = 33.50 - 26.46 = 7.04
For number of hours worked = 12,
Observed amount ( from table) is 25.00
Predicted amount (using equation) is
[tex]\begin{gathered} y=0.4x+23.26 \\ y=0.4(12)+23.26 \\ y=28.06 \end{gathered}[/tex]Residual = 25 - 28.06 = -3.06