
Hilary W. answered 10/21/14
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With direct variation, an increase in concentration leads to an increase in absorbance. We can assume that the curve passes through (0,0), where a concentration of zero leads to zero absorbance. Therefore there is a positive linear relationship. If the concentration is tripled, the absorbance will also triple.
Allow A=abs.
Allow x = conc. in mg/dL
Allow m = slope
if A = 0.3 and x=100;
0.3 = 100*m
m = 0.3/100 = 0.003.
A = 0.003x
Solve for x = 300
A = 0.003*(300) = 0.9