Consider the plot of log against I 1/2 with B=1.50 and C=0 in the Davies

Consider the plot of log γ_± against I^1/2 with B=1.50 and C=0 in the Davies equation as a representation of experimental data for a certain MX electrolyte. Over what range of ionic strengths does the application of the limiting law lead to an error in the value of the activity coefficient of less than 10 per cent of the value predicted by the extended law?