Answer:
The value is [tex]z = -2.5[/tex]
Step-by-step explanation:
From the question we are told that
The the random selected observation [tex]x = 25[/tex]
The mean is [tex]\mu = 50[/tex]
The standard deviation is [tex]\sigma = 10[/tex]
Generally z score is mathematically represented as
[tex]z = \frac{x - \mu}{\sigma }[/tex]
=> [tex]z = \frac{25 - 50}{10 }[/tex]
=> [tex]z = -2.5[/tex]
