If $(t_1, y_1), (t_2, y_2), (t_3, y_3),... (t_n, y_n)$ denote the time series and $y_t$, are the trend values of the variable $y$, then $\sum(y-y_t)$, the sum of deviations of $y$ from their corresponding trend value is equal to:

0

The correct answer is Option (3) → 0 **

$\sum (y - y_t)$

For any time–series trend line, the sum of deviations of the actual values from their corresponding trend values is always

$0$

The required value of $\sum (y - y_t)$ is $0$.