What’s the difference between a mixture and a substance

A mixture is a material produced by mixing two or more distinct components in such a manner that there is no chemical response. Every component of purity is a substance. Every pure compound is a substance.

93.2 ml + 3920 ml = 4013 ml total  

(93.2 ml) * (2.03 m) / (4013 ml) = 0.0471 m

the volume in in l of the diluted solution would be 0.0471 m.