It's correct, of course, as the problem is solved, but most people would attempt a ballpark approximation in the end!
Professor John Wermer tells the story of how, when he was an undergraduate, he took a course in projective geometry from Oscar Zariski, one of the foremost figures in the field of algebraic geometry. Zariski's course was exceedingly general and Wermer, as a young student, was occasionally in need of clarification. "What would you get," he asked his teacher, "if you specialized the field F to the complex numbers?" Zariski answered, "Yes, just take F as the complex numbers."