Yes, weight by volume,
The important thing to remember when dealing with either one is that you're always working with mass, so even if you have weight by volume, you're still going to use mass, as opposed to weight.
This means that in order to find your solution's
To do that, use the known composition as a conversion factor
#100 color(red)(cancel(color(black)("mL solution"))) * "8.00 g dextrose"/(275 color(red)(cancel(color(black)("mL solution")))) = "2.91 g dextrose"#
This means that the solution's mass by volume percent concentration will be
#color(darkgreen)(ul(color(black)("% m/v " = " 2.91% dextrose")))#
The answer is rounded to three sig figs.