ESF$\mathrm{.}3($a$)$ Estimate the mean ionic activity coefficient of $CaC{l}_2$ in a solution that is $0\mathrm{.}010molk{g}^{-1}CaC{l}_2(aq)$ and $0\mathrm{.}030molk{g}^{-1}$NaF$(aq)$ at $25C.$

ESF$\mathrm{.}3($b$)$ Estimate the mean ionic activity coefficient of NaCl in a solution that is $0\mathrm{.}020molk{g}^{-1}$NaCl$(aq)$ and $0\mathrm{.}035molk{g}^{-1}Ca(N{O}_3{)}_2(aq)$ at $25C.$