Answer:
The formula to calculate the mean (\(\bar{X}\)) is:
\[ \bar{X} = \frac{\sum{fi \cdot ui}}{\sum{fi}} \]
where \(fi\) is the frequency, and \(ui\) is the class midpoint.
In your case:
\[ \bar{X} = \frac{-36}{35} \]
Therefore, the mean is approximately \(-1.029\).
