$5-13/6$ A $150-$hp$,3-$phase, wye$-$connected, $\backslash (60-\backslash$mathrm$\{$Hz$\},4000-\backslash$mathrm$\{$V$\}\backslash ),$ six$-$pole induction motor, operating at rated conditions from an isolated power system has a shaft speed of $1175$ r$/$min$.$ A very heavy power demand on the electrical system caused the voltage and frequency to decrease by $15$ and $5$ percent, respectively. To compensate for this off$-$normal condition, the torque load on the motor was reduced to $82$ percent of rated torque: Determine the operating speed for the new conditions.