Hi Robert and Sander,
These are the datasets:
data = List[{{5.44, 1.}, {13.44, 1.31351}, {21.44, 1.74846}, {29.44,
1.83433}, {37.44, 2.06847}, {53.44, 2.36553}, {77.44, 2.53351}}]
and
data2 = List[{d * p, y110}, {(1 + d) * p, y210}],
where d = 0.68 and p = 8.
They plot nicely (in Black) from
Show[ListPlot[data2], ListPlot[data], PlotRange -> All]
Strange