We have a first order kinetics.
Let's call:
[tex]\begin{gathered} \lbrack Ao\rbrack\text{ = Concentration of virus. Initial at to} \\ \lbrack A\rbrack\text{ = Final Conc. }at\text{ t} \end{gathered}[/tex][tex]\begin{gathered} to\text{ Initial time} \\ t\text{ final time} \end{gathered}[/tex][tex]\lbrack A\rbrack\text{ = }\lbrack Ao\rbrack\text{ x }e^{-k\text{ x t }}[/tex]That is the formula to calculate the concentration of the virus
You can have it from this:
[tex]-\frac{d\lbrack A\rbrack}{dt}\text{ = k }\lbrack A\rbrack[/tex]we don't have the "k" specific velocity constant
Half-life is when (A) = (Ao)/2
We have t=4.5 h ar 29.6%
[tex]\frac{0.296}{2}=\text{ 0.296 }e^{-k\text{ x 4.5}}\text{ }[/tex]Then k= 0.15 1/h
At first order, half-time doesn't depend on Concentration
So, the time it is going to be the same:
[tex]\frac{0.37}{2}=0.37\text{ x }e^{-0.15xt}[/tex]Then the half-time will be 4.5 h.