To solve this there is this website that I found that helps
I am in middle school so I have no idea how to solve this
but
this website may help considering u are in high school and u
(hopefully mind u)
know how to solve this
so to get there u google
"whats impact speed"
and click on the first thing there the website is ehow
The equation for percent error is
% Error =

Our experimental is 2.85g/cm^3 and the accepted is 2.7g/cm^3
Thus our % Error = 5.555%
The answers is A and C hope this helps :)