A cell-surface receptor ligand binding affinity was measured to be Kd = 0.5 nM at 4C to prevent receptor endocytic trafficking. Using the approximate relationship represented in figure 2.4, estimate the range of likely values for Kd at 37C.

The numerical answer is 1.25-3.5 nm but I don't know how to get there

Figure 2.4:

H(kcal/mol)051020