The answer would be .40008L
The word milli- translates to [tex] \frac{1}{1000} [/tex] units. In this case, we have liters as our base unit. So a milliliter is [tex] \frac{1}{1000} [/tex] Liters or you can say that there are:
1,000 mL in 1 L.
As I understand, you are trying to convert 400.08mL to L.
So this is how you are going to get it:
[tex]400.08mL[/tex] x [tex] \frac{1L}{1,000mL} [/tex]
= [tex] \frac{400.08L}{1,000} = 0.40008L[/tex]