Answer:
85
Explanation:
First, recall the formula for Z-Score.
[tex]Z-\text{Score}=\frac{X-\mu}{\sigma}\text{ where }\begin{cases}X=\text{raw score} \\ \mu=\operatorname{mean} \\ \sigma=\text{standard deviation}\end{cases}[/tex]Substitute the given values:
[tex]\begin{gathered} -1.5=\frac{X-100}{10}\text{ } \\ X-100=-1.5\times10 \\ X-100=-15 \\ X=100-15 \\ X=85 \end{gathered}[/tex]A z-score of -1.5 represents an IQ score of 85.
