Which of the following is not true of a stationary time series? ...

[jazziefee]

Which of the following is not true of a stationary time series?
 a. The process generating the data has a constant mean.
  b. The time series plot is a straight line.
  c. The statistical properties are independent of time.
  d. The variability is constant over time.

Question 2

In order to visualize three variables in a two-dimensional graph, we use a
 a. 2-D chart. b. 3-D chart.
  c. bubble chart. d. column chart.

[pratush dev]

Answer to Question 1

b
RATIONALE: The term stationary time series is used to denote a time series whose statistical properties are independent of time. In particular this means that the process of generating the data has a constant mean and the variability of the time series is constant over time.

Answer to Question 2

c
RATIONALE: A bubble chart is a graphical means of visualizing three variables in a two-dimensional graph and is, therefore, sometimes a preferred alternative to a 3-D graph.