(mmol/L) concentration absorbance 2.9 0.1225 5.8 0.2125 8.7 0.465 11.6 0.551 14.5 0.842 17.4 1.0184 20.3 1.113 0.061087438 -0.090842857 tcrit= 1.98678943 0.003525542 0.045723445 0.98361883 0.05410071 critical value= 2.570581836 300.2285106 5 0.87873486 0.014634434 tcrit