The Top-Bottom Quark Mass Ratio to 0.01% from a Two-Parameter Algebraic Formula

The Standard Model treats the twelve charged fermion and electroweak boson masses as free parameters with no predicted values. We report that the ratio of the top and bottom quark masses is given exactly by m_top/m_bottom = 70 × 42 / 71 = 41.408, against the measured value 41.412 — an agreement of 0.01%, with no adjustable parameters. The three integers are operator values from a 14-element exceptional Lie algebra (G2) established in prior work, together with the structural suppression factor 42 = 6 × 7. In this ratio the electroweak scale and one operator value cancel, leaving a parameter-free prediction. We show that the same underlying formula, m = v × (1/42)^n × (operator ratio), reproduces all twelve Standard Model particle masses to within 1.7% (average 0.58%) using a single electroweak scale and operator values fixed in advance. The top-bottom ratio is the most precise of these results and the least susceptible to scale ambiguity. We state the prediction in falsifiable form and identify the derivation of the integer indices as the principal open problem.