Answer
PART A
i) z $\approx$ -1.15
ii) z $\approx$ 0.17
iii) z $\approx$ -2.28
iv) z = $\approx$ 2.62
PART B
$x$ = 9 and $x$ = 35 are both unusual values
Work Step by Step
PART A
Use the formula z = $\frac{x - \mu}{\sigma}$ to convert $x$ values to z scores.
i) z = $\frac{15 - 21.1}{5.3}$ $\approx$ -1.15
ii) z = $\frac{22 - 21.1}{5.3}$ $\approx$ 0.17
iii) z = $\frac{9 - 21.1}{5.3}$ $\approx$ -2.28
iv) z = $\frac{35 - 21.1}{5.3}$ $\approx$ 2.62
PART B
$x$ = 9 and $x$ = 35 are both unusual values because they both are more than 2 standard deviations away from the mean (as seen by their respective z scores, z $\approx$ -2.28 and z $\approx$ 2.62).
