An earthquake on the ocean floor in the Gulf of Alaska induces a tsunami (sometimes called a "tidal wave") that reaches Hilo, Hawaii, 4780 km away, after a time of 9.99 h. Tsunami’s have enormous wavelengths (100- 200 km), and for such waves the propagation speed is v ≈ qgd , where d is the average depth of the water, d is in meters, v is in m/s, and g = 9.8 m/s^2 . From the information given, find the average ocean depth between Alaska and Hawaii.