Example $1$

$1$ point possible $($graded$)$

Consider the following realizations of a time series model, with increasing levels of noise from top to bottom:

What trend and$/$or seasonality do the series above exhibit?

$($The noise level of the series in the third figure is very high relative to the magnitude of other components of the series. This makes detecting this structure difficult for the naked eye. Use the first two figures to identify the structural properties of the series and extrapolate them to the third figure.$)$

$($Choose all that apply.$)$