Answer: Not unusual.
Step-by-step explanation:
We know that the z-scores lower than -1.96 or higher than 1.96 are considered as unusual.
Given : Sample size : n= 65
Sample mean = [tex]\mu= 212[/tex]
Standard deviation : [tex]\sigma=5.8[/tex]
Formula for z-score : [tex]z=\dfrac{x-\mu}{\sigma}[/tex]
At x= 213
[tex]z=\dfrac{213-212}{5.8}=0.172413793103\approx0.17[/tex]
Since , -1.96< 0.17 <1.96
It means the probability of a sample mean being greater than 213 is not unusual.
