  We present evidence of $D^0$-$\bar{D^0}$ mixing using a time-dependent
amplitude analysis of the decay D0->K+pi-pi0 in a data sample of 384 fb^-1
collected with the BaBar detector at the PEP-II e+e- collider at SLAC. Assuming
CP conservation, we measure the mixing parameters x'_{Kpipi0} =
[2.61^{+0.57}_{-0.68} (stat.) +- 0.39 (syst.)]%, y'_{Kpipi0} = [-0.06
^{+0.55}_{-0.64} (stat.) +- 0.34 (syst.)]%. The confidence level for the data
to be consistent with the no-mixing hypothesis is 0.1%, including systematic
uncertainties. This result is inconsistent with the no-mixing hypothesis with a
significance of 3.2 standard deviations. We find no evidence of CP violation in
mixing.
