Flight La Guardia Airport departs from New York La Guardia Airport at 11:15 and arrives at Seattle Tacoma International Airport at 18:40.The flight has a short stop at Chicago.
The flighttime is about 10h 25m. The distance travelled ("as the bird flies"): 5376 Km. So the average speed is roughly 516 Km.
There is an 3 hour time difference between New York and Seattle