The \(t\)-distribution is symmetric around zero and approximates the standard normal distribution as the degrees of freedom increase.
For a \(t\)-distribution with degrees of freedom \(u > 1\), the mean is defined and equals 0.
This is due to the \(t\)-distribution being centered at 0 and having a bell-shaped curve.
However, when \(u \leq 1\), the mean is undefined.
In typical statistical applications where \(u > 1\) (frequent in practice), the mean is taken as 0.
Therefore, the correct answer is \(0\).
Find the median of the following data : 
Find the mode of the following frequency table : 
The modal class of the following frequency table will be : 
The median class of the following frequency distribution will be : 