16.684 x a

$\frac{16.684*a}{14b*(10a)}>16\\ \frac{16.684a}{140ba}>16\qquad a\ne0\quad and \quad b\ne0 \\ \frac{16.684}{140b}>16\\ \frac{16.684}{b}>16*140\\ \frac{16.684}{b}>2240\\ \frac{16.684}{b}*\frac{b^2}{1}>2240*\frac{b^2}{1}\\ 16.684b>2240b^2\\ 0>2240b^2-16.684b\\ b(2240b-16.684)<0$

Consider y=b(2240b-16.684)

This is a concave up parabola  

The roots are b=0 and   2240b-16.684=0

The roots are b=0 and   b=16.684/2240

The roots are b=0 and   b=417/56000

The parabola will have negative y value when b is between 0 and 417/56000

That is                          

$0 < b < \frac{417}{56000}    \qquad and \;\;a\in R \;\;\;where\;\;\;\; a\ne0$