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

Which of the following graph plotted for the months against the three month moving average(3Yr MA) represents the given data correctly ?

[Four line graphs labelled 1-4, each plotting 3-Yr MA against month, showing different curve shapes and values]

In a time series, the variations which occur due to general tendency of the data to increase or decrease over a long term are known as:

For the given five values 10, a, 13, b, 25, the 3-years moving averages are 15, 18, 19. The value of a+b is

For a straight line trend $y_t = a+bx$ for $n$ data by the method of least squares if, $n=8, \sum y=47.8, \sum xy=4.3$ and $\sum x^2=42$, then $y_t$ at $x=-3.5$ is _____.

[where $y_t$ represents trend value of y]

Which of the following are correct?

(A) Time series analysis does not help to understand the behavior of a variable in the past.

(B) Time series predict the future behavior of variable.

(C) Time series helps to plan future operations.

(D) The main aim of the time series analysis is to derive conclusions after arranging the time series in a systematic manner.

Choose the correct answer from the options given below:

If three year moving averages for five data items given by 16, 18, 20, 10, 21 are $x$, $y$ and $z$ respectively, then: