Firstly we will determine the average or the mean of the objects density:
![\begin{gathered} Mean=(1.3g•mL^(-1)+1.25g•mL^(-1)+1.17g•mL^(-1)+1.22g•mL^(-1))/(4) \\ Mean=(4.94g•mL^(-1))/(4) \\ Mean=1.235 \end{gathered}](https://img.qammunity.org/2023/formulas/chemistry/college/4bf4nqkktzoqy0xvtcf4w2ol065xqo96s7.png)
Now we will calculate the deviation. The deviation is how much is trial is different from the average. We take the absolute value so the answers can be positive:
![\begin{gathered} Trial\text{ }1:|1.3-1.235|=0.065 \\ Trial\text{ }2:|1.25-1.235|=0.015 \\ Trial\text{ }3:|1.17-1.235|=0.065 \\ Trial\text{ }4:|1.22-1.235|=0.015 \end{gathered}](https://img.qammunity.org/2023/formulas/chemistry/college/91jpiq2g3hdd45e11g4rid1z1h6m5u7kse.png)
We will determine the average of the deviation:
![\begin{gathered} Deviation\text{ }mean=(0.065+0.015+0.065+0.015)/(4) \\ Deviation\text{ }mean=0.04 \end{gathered}](https://img.qammunity.org/2023/formulas/chemistry/college/zozzzckujpgdea168rjue0p8xh5jr1i0xi.png)
To determine the percent deviation we:
![\begin{gathered} \%\text{ }deviation=\frac{mean\text{ }deviation}{mean}*100 \\ \\ \%\text{ }deviation=(0.04)/(1.235)*100 \\ \\ \%\text{ }deviation=3.24\% \end{gathered}](https://img.qammunity.org/2023/formulas/chemistry/college/37wyx1bt2560thda4y9nhay2al0p8nbfux.png)
Answer: The percent deviation from the mean is 3.24%,