We have that the 100% of the weight is 14.25 pounds. Then, using a rule of three, we can find the percent change to 16 pounds:
[tex]\begin{gathered} 14.25\rightarrow100\% \\ 16\rightarrow x\% \\ \Rightarrow x=\frac{16\cdot100}{14.25}=\frac{1600}{14.25}=112.3 \\ x=112.3 \end{gathered}[/tex]then the percent change is:
[tex]112.3\%-100\%=12.3\%[/tex]therefore, the percent error of Oliver's estimate is 12.3%