An 11kV/415V Delta/Star transformer powers a load which contains a total of ten 3-Phase induction motors, each rated at 15kW, 0.75 efficiency and with a power factor of 0.8 lagging.

Determine the per phase apparent power (S).

The answer in the book identifies the apparent phase power as
83.33kV A∠36.87°

However I tried calculating this particular way below

S = P x cos(Φ)
..S = (10x15/0.75) x 0.8
S = 160
PhasePower = 160/√3
PhasePower = 92.34kV A∠36.87°