[tex]2.3=10(1-e^{3.25k}))\\
2.3=10-10e^{3.25k}\\
10e^{3.25k}=7.7\\
e^{3.25k}=0.77\\
3.25k=\ln 0.77\\
k=\frac{\ln 0.77}{3.25}\\
k\approx-0.0804
[/tex]
[tex]S=10(1-e^{\frac{\ln 0.77}{3.25}\cdot4.25})\\
[/tex]
Calculating this is a pain in the ***, but as a result you get approximately 2.8949 which in thousands of units is 2894 (rounded down since you can't have a fraction of a unit).
