The following weight loss data were observed for the atmospheric corrosion of plain carbon steel in an industrial atmosphere [79]: Time (years) 0.0 0.5 1.0 2.0 3.0 4.0 5.0 7.0 Weight loss (mg/cm²) 0.0 51.5 82.7 149.3 189.9 226.9 257.8 295.2 (a) What is the instantaneous corrosion rate in milligrams per square centimeter per year at 1 year exposure?