$4.(6$ pts$)$ A nitrocellulose filter binding assay was used to measure the binding affinity for an experimental leukemia drug, which binds to phosphoinositide $3-$kinase alpha $($PI$3$K $).$ Using logarithmic graph paper or a spreadsheet program to make a logarithmic plot of the binding isotherm and determine the dissociation constant $(\backslash (\backslash$mathrm$\{$K$\}\_\{\backslash$mathrm$\{$I$\}\}\backslash )).($See Fig. $12\mathrm{.}8)$