The case related to exercise n. 10

My question: Why sampling error is negative, what does it means and **how it’s possible that no one asked this question before?!** It seems to be an important part of understanding a sample error.

in this case the age mean of your sampled group was 1.4 lower than the original datasets age mean, thus it’s a negative number

BMI mean of your sample was 0.23 higher than the mean of original dataset so a ‘positive’ error (not sure if we can call it like that, lets just say positive value)

So it means that sampling error must be positive from the **“zero”** which needs to be defined because it’s not trivial zero. Good to know. Thank you for your reply!