Answer:
The standard error of the mean is [tex]\sigma _{\= x } = 1.581[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is n = 250
The standard deviation is [tex]\sigma = 25[/tex]
The sample mean is [tex]\= x = 20[/tex]
The standard error of the mean is mathematically represented as
[tex]\sigma _{\= x } = \frac{\sigma }{\sqrt{n} }[/tex]
substituting values
[tex]\sigma _{\= x } = \frac{25 }{\sqrt{250} }[/tex]
[tex]\sigma _{\= x } = 1.581[/tex]
