Answer: C) 1.5
The given point (2,5) is in the form (x,y). So x = 2 and y = 5.
Plug x = 2 into the equation given to find the predicted y value
y = 2.5x - 1.5
y = 2.5(2) - 1.5
y = 5 - 1.5
y = 3.5
We get a predicted y value of 3.5, and the actual y value is 5. Subtract the two values in this exact order
residual = (actual) - (predicted) = 5 - 3.5 = 1.5
A positive residual means that our predicted value is too small. A negative residual would be that the predicted value is too large.