A modified Taylor tool life equation is given as follows:
\[ V T^n f^m = constant \]
where \( V \) is the cutting speed (m/s), \( T \) is the tool life in minutes and \( f \) is the feed in mm/rev, \( n = 0.25 \) and \( m = 0.5 \). Under two different cutting conditions \( (V_1, f_1) \) and \( (V_2, f_2) \) the tool life \( (T_1, T_2) \) was found to be the same.
If the ratio of the cutting speeds \( (V_1/V_2) \) used is 2/3, then the ratio of corresponding feeds \( (f_1/f_2) \) must be ______ (rounded off to two decimal places).