Answer:
[tex]Z=2.49[/tex] and this Z-score is “unusual.”
Step-by-step explanation:
To calculate the Z score use the following formula
[tex]Z=\frac{x-\mu}{\sigma}[/tex]
Where
μ is the average
[tex]\sigma[/tex] is the standard deviation
x is the data to which we will calculate the z-score
In this case
[tex]\mu = 122.3\\\\\sigma= 18.5\\\\x =168.4[/tex]
So
[tex]Z=\frac{168.4-122.3}{18.5}[/tex]
[tex]Z=2.49[/tex]
A z-score is unusual if [tex]Z> 2[/tex] or [tex]Z < -2[/tex]
Finally
[tex]Z=2.49[/tex] and this Z-score is “unusual.”