Average Acceleration from Velocity Vector

The velocity of a particle moving in the xy-plane is given by the function $\vec{v}(t) = (3t^2 \hat{i} + 4t^3 \hat{j})$ m/s, where $t$ is time in seconds. What is the magnitude of the particle’s average acceleration over the time interval from $t = 1$ s to $t = 2$ s?