(a) The standard deviation of the log(t_dep) at different scales, calculated by three different methods for the pixel-by-pixel analysis. Fit shows the result from a Gaussian fit to the distribution of log(t_dep) for all data points with positive flux. Limit refers to the standard deviation of the log(t_dep) after upper limits were assigned to and Σ_SFR. EM refers to the standard deviation from the expectation-maximization method, which estimated the censored data assuming a normal distribution of log(t_dep). (b) Comparisons of the standard deviation of the log(t_dep) between the Galactic plane from this study and the extragalactic studies of M51 (a) by Blanc et al. (2009, B09), NGC 5194 by Kennicutt et al. (2007, K07), M33 by Schruba et al. (2010, S10), and Leroy et al. (2013, NGC 4725, NGC 6946, NGC 4736). All of the data for extragalactic studies were taken from Leroy et al. (2013).