Figure 4. The weighted residual errors for all 65 participants for three different pharmacokinetic models. The weighted residual errors are shown as measured/predicted on a logarithmic scale. The line drawn at y = 1 represents a perfect prediction. The upper panel shows the simple model without covariates. The middle panel shows a simple lean body mass proportional model. The lower panel shows the complex model with age and lean body mass as covariates.