The velocity graph of a particle moving along the x-axis is shown. The particle has zero velocity at t=0.00 s and reaches a maximum velocity, vmax, after a total elapsed time, ttotal. If the initial position of the particle is x0=7.28 m, the maximum velocity of the particle is vmax=33.4 m/s, and the total elapsed time is ttotal=20.3 s, what is the particle's position at t=13.5 s?