Answer
i) z = -0.75
ii) z = 1.56
iii) z = -2.48
iv) z = 0.40
Work Step by Step
To convert an x value to the z-score, use the following formula:
z = $\frac{x - \mu}{\sigma}$
In the question, we are given $\mu$ = 20.9, $\sigma$ = 5.2
So:
i) Convert $x$ = 17
z = $\frac{17-20.9}{5.2}$ $\approx$ -0.75
ii) Convert $x$ = 29
z = $\frac{29-20.9}{5.2}$ $\approx$ 1.56
iii) Convert $x$ = 8
z = $\frac{8-20.9}{5.2}$ $\approx$ -2.48
iv) Convert $x$ = 23
z = $\frac{23-20.9}{5.2}$ $\approx$ 0.40
