Please solve the answer properly. The 1620 rpm is not the actual rpm in the shaft and shaft power 26.5hp is wrong answer

[answerhappygod]

Please solve the answer properly. The 1620 rpm is not the actual
rpm in the shaft and shaft power 26.5hp is wrong answer. Here is
the problem:
a three phase wye connected, 50hp 60hz 4000v six pole induction
motor operating at rated condition has an efficiency, power factor
and slip of 89.6%, 79.5% and 3% respectively. operating the motor
from 430V 55hz supple results in a shaft speed of 1750rpm.
Determine the resultant shaft power for the new operating
conditions.