A method of analysis yields masses of gold that are low by 0.4 mg. Calculate the percent relative error caused by this result if the mass of gold in the sample is ...
a. 400 mg
b. 230 mg
c. 160 mg
d. 10 mg
I've tried divding each number by 0.4mg and that doesnt give me the right answer. If you could give me the correct way to perform this problem that would be great