Answer:
C. Usual, because the result is within the range of the minimum and maximum usual values.
Step-by-step explanation:
When the z-scores is lower than -1.96 or higher than 1.96, they are considered as unusual and interesting and they are statistically significant outliers.
The Z score can be calculated by,
[tex]Z=\dfrac{X-\mu}{\sigma}[/tex]
where,
X = raw score = 622.3
μ = mean = 674
σ = standard deviation = 26.6
Putting tall the values,
[tex]Z=\dfrac{622.3-674}{26.6}=-1.94[/tex]
As [tex]-1.96<-1.94<1.96[/tex], so the result is usual, because it lies within the range of the minimum and maximum usual values.
