A calcium ion ISE gives a response of \(+170 \mathrm{mV}\) in a \(100.00 \mathrm{ml}\) sample solution. The same solution is spiked with \(5.00 \mathrm{ml}\) of \(0.125 \mathrm{M}\) calcium standard solution. After thorough mixing the same electrode combination gave a reading of \(+193 \mathrm{mV}\). Assuming a Nernstian response and no interferences, calculate the concentration of \(\mathrm{Ca}^{2+}\) in the original sample solution.