Nthe video, the water level was 15 milliliters before adding the chain, and 20 milliliters after adding the chain. when i weighed the chain, its mass was 67.2 grams.

i believe the chain is solid metal (not gold plated), but is probably a blend of gold and other metals. i looked up that gold has a density of 19.3 g/ml, while the other metals like silver and copper usually blended with gold have a combined density of about 9.7 g/ml.

determine what percentage of the chain is gold, by mass, to at least 1 decimal place?