Question

 The mean IQ is 100 with a standard deviation of 15. The Z-score of an IQ of 117 is 

Answer 1

$X\sim (\mu, \sigma^2)$

Given $\mu=100, \sigma=15$

$$Z=\dfrac{X-\mu}{\sigma}=\dfrac{117-100}{15}=\dfrac{17}{15}\approx1.133333$$

$$Z=\dfrac{17}{15}\approx1.133333$$