Answer: -144
The summation of these indexed data then can be calculated by the sima notation. According to these scheme below:
[tex]\begin{gathered} 29+\sum ^{12}_{n\mathop=1}x_1 \\ 29+(-173) \\ -144 \end{gathered}[/tex]Because:
The Sigma represents the summation of all these 12 data entries starting from the first one, according to this function in which x_1=is labeled as the first entry x_2, the second and so on.