Here \displaystyle F\le \mu R
\displaystyle \mu is the coefficient of friction.
\displaystyle \begin{align} & 67\textrm{.}0<\mu 184 \\ & \\ & \mu >\frac{67\textrm{.}0}{184} \\ & \\ & \mu >0\textrm{.}364 \\ \end{align}
