For the five values 12, $a$, 17, 21, 22, the three years moving averages are 13, 16, 20. The value of $a$ is

Which of the following statements are correct?

A. If $x_1,x_2,x_3,\dots,x_n$ is the given annual time series, then 3-yearly moving averages are $\dfrac{x_1+x_2+x_3}{3},\dfrac{x_2+x_3+x_4}{3},\dots\dots$

B. In the method of the least squares, if $(t_1,y_1),(t_2,y_2),\dots(t_n,y_n)$ denote the time series and $y_t$ are trend values of $y$, then $\sum(y-y_t)=0$

C. In the method of the least squares, the sum of squares of the deviations of the values of $y$ from their corresponding trend values is least.

D. The rise in prices before Diwali is an example of a cyclical trend.

Choose the correct answer from the options given below:

For the given five values 18, 25, 20, 36, 49, the three years moving averages are

A company is shut down due to unavailability of electricity due to non payment of electricity Bill because of some unavoidable circumstances. Under which component of time series does this situation fall?

For the values 22, 25, 28, 31, 40, 43, the three yearly moving averages are

When data of the variable is collected at distinct time intervals for a specified period of time, it is called

Which of the following is not a component of the time series?