The following data come from the calibration of a proving ring, a device for measuring f...

The following data come from the calibration of a proving ring, a device for measuring force (Hockersmith and Ku 1969).

a. Plot load versus deflection. Does the plot look linear?

b. Fit deflection as a linear function of load, and plot the residuals versus load. Do the residuals show any systematic lack of fit?

c. Fit deflection as a quadratic function of load, and estimate the coefficients and their standard errors. Plot the residuals. Does the fit look reasonable?