For a normal distribution, we have the mean μ and the standard deviation σ:
[tex]\begin{gathered} \mu=11 \\ \sigma=4 \end{gathered}[/tex]The z-score can be calculated using the formula:
[tex]Z=\frac{X-\mu}{\sigma}[/tex]Where X is a score from the normal distribution. For X = 17, we have:
[tex]\begin{gathered} Z=\frac{17-11}{4}=\frac{6}{4} \\ \\ \therefore Z=1.5 \end{gathered}[/tex]