what is 19 over 50 out of 4200?

$${\frac{{\frac{{\mathtt{19}}}{{\mathtt{50}}}}}{{\mathtt{4\,200}}}} = {\mathtt{0.000\: \!090\: \!476\: \!190\: \!476\: \!2}}$$ The problem is just one big fraction that a calculator would be most useful in solving for.