Percentage of Errors help?

I'm doing a lab about the densities of several different metals and liquids. I have all my data averages for each material, and now we have to find the percentage error based on the theoretical average density of each one.
I keep getting a huge percentage error, which I know isn't right because I know I did my lab correctly.

But for example: the national average density of zinc is 7.140 g/mL. The zinc I was using had a weight of 67.4 g, and an average density of 2.1 g/mL.

I feel as if the weight is messing up my formulas? Please help!

Question

Percentage of Errors help?

I'm doing a lab about the densities of several different metals and liquids. I have all my data averages for each material, and now we have to find the percentage error based on the theoretical average density of each one.
I keep getting a huge percentage error, which I know isn't right because I know I did my lab correctly.

But for example: the national average density of zinc is 7.140 g/mL. The zinc I was using had a weight of 67.4 g, and an average density of 2.1 g/mL.

I feel as if the weight is messing up my formulas? Please help!

aaronq · Answer

Thats a large deviation, wanna provide more info on how you did the average calculations maybe even an example?