To find the z-score we use the following formula:
[tex]z-score=\frac{x-\mu}{\sigma}[/tex]Where x is the data point or the element, in this case:
[tex]x=57[/tex]μ is the mean:
[tex]\mu=68.42[/tex]and σ is the standard deviation:
[tex]\sigma=7.91[/tex]--> Substituting these three values into the z-score formula
[tex]z-\text{score}=\frac{57-68.42}{7.91}[/tex]Solving the operations:
[tex]\begin{gathered} z-\text{score}=\frac{-11.72}{7.91} \\ \\ z-\text{score}=-1.48167 \end{gathered}[/tex]Finally, we need to round to the nearest hundredth (2 decimal places):
[tex]z-\text{score}=-1.48[/tex]Answer: -1.48
