Alinear regression was conducted on the following data points.

a(1, 11) b(3, 7) c(5, 2) d(7, 1) e(9, -2)

the residual for which point has the largest absolute value?

Using MS Excel, we plot the data points and find the trend line. The equation of the line is  y=-1.6x+11.8. The equation of the line has no r2 of 1 which means there is a discrepancy of the values. W predict the y-value for each x through substitution.
 y(1)=10.2; y(3)=7; y(5)=3.8; y(7)=0.6 and y(9)=-2.6 

Residual = Observed - Predicted 
Hence for each y, 
11-10.2 = .8 
7-7 = 0 
3.8 - 2 = 1.8 
1-0.6=0.4 
2.6 - 2 = 0.6 
The largest absolute value is 1.8 from the point C(5,2).