The iron content of slag can be estimated magnetically, or measured chemi cally. The magnetic method is quicker and easier, but the chemical method is more precise. Five slag samples are measured both ways.
(a) Use the data given below to estimate the linear relationship between Y = chemical yield and x = magnetic measurement.
Magnetic: 22 19 25 21 28
Chemical: 24 21 25 23 25
(b) Estimate a2 and explain what it measures in the context of this prob lem.
(c) Plot the residuals from the linear model against the magnetic readings and comment on the model.