In order to calculate the acceleration of gravity, we can use the free fall formula:
[tex]d=\frac{gt^2}{2}\to g=\frac{2d}{t^2}[/tex]Where d is the distance travelled and t is the time.
So for each distance in the chart, we have:
[tex]\begin{gathered} d=0.2\colon \\ g=\frac{0.4}{0.184^2}=11.81 \\ \\ d=0.4\colon \\ g=\frac{0.8}{0.258^2}=12.02 \\ \\ d=0.6\colon \\ g=\frac{1.2}{0.4^2}=7.5 \\ \\ d=0.8\colon \\ g=\frac{1.6}{0.236^2}=28.73 \\ \\ d=1\colon \\ g=\frac{2}{0.33^2}=18.37 \end{gathered}[/tex](All gravity units in m/s²)
Now, calculating the average, we have:
[tex]g=\frac{11.81+12.02+7.5+28.73+18.37}{5}=15.69[/tex]Finally, calculating the percent error, we have:
[tex]\text{Percent error}=\frac{|9.81-15.69|}{9.81}=0.5994=59.94\text{\%}[/tex]