(29) Consider trying to determine the calibration curve for gas chromatography based on some sample measurements with known ratios. Assume that the 140 3 Regression Table 3.13 Gas chromatography calibration data (for Question 29)

Measured ratio (y) Known ratio (x)

1.000 0.2 0.987 0.3 1.347 0.6 2.856 1.3 4.476 2.6 5.148 4.0 Table 3.14 Time constant

(τ ) as a function of the water level (h) (for Question 30)

Time constant, τ (s) Level, h (m)

51.7 0.1 82.8 0.15 91 0.2 97.2 0.25 101.4 0.3 107.6 0.35 variance is proportional to x2.Use the data provided in Table 3.13 to fit a linear model to the data. Analyse the residuals and model adequacy to determine how good the fit is