Lexical error on line 1. Unrecognized text. ... \right) = {\mathop{\rm sgn}} \left( {{\ -----------------------^ y\left( x \right) = {\mathop{\rm sgn}} \left( {{\rho }} \right)\frac{{{\sigma _y}}}{{{\sigma _x}}}\left( {x - {\mu _x}} \right) + {\mu _y}