Part (a)
Using the formula for the z-scores and the information given, we have:
[tex]\begin{gathered} \text{ z-score=}\frac{\text{ data value }-\text{ mean}}{\text{ standard deviation }} \\ \text{ z-score=}\frac{1.7\text{ cm }-\text{ 1.3 cm}}{0.3\text{ cm}} \\ \text{ z-score=}\frac{0.4\text{ cm}}{0.3\text{ cm}}\text{ (Subtracting)} \\ \text{ z-score=1.33 (Dividing)} \\ \text{The z-score for 1.7 cm is 1.33 rounding to the nearest hundredth.} \end{gathered}[/tex]
Part (b)
Using the formula for the z-scores and the information given, we have:
[tex]\begin{gathered} \text{ z-score=}\frac{\text{ data value }-\text{ mean}}{\text{ standard deviation }} \\ \text{z-score=}\frac{\text{ 0.9 cm }-1.3\text{ cm}}{\text{ 0.3 }}\text{ (Replacing the values)} \\ \text{z-score=}\frac{\text{ }-0.4}{\text{ 0.3 }}\text{ (Subtracting)} \\ \text{ z-score= }-1.33 \\ \text{The z-score for 0.9 cm is -1.33 rounding to the nearest hundredth.} \end{gathered}[/tex]
