The following is a portion of a classic data set called the "pilot plot data" in Fitting Equations to Data by Daniel and Wood, published in 1971.
The response y is the acid content of material produced by titration whereas the regress or X is the organic acid content produced by extraction and weighing.
(a) Plot the data; does it appear that a simple linear regression will be a suitable model?
(b) Fit a simple linear regression; estimate a slope and intercept.
(c) Graph the regression fine on the plot in(a).