It can be seen from the two time series plots in Figure 4.3 that the application of the two-point moving average to the white noise sequence smoothes the sample path. This is due to an attenuation of ...It can be seen from the two time series plots in Figure 4.3 that the application of the two-point moving average to the white noise sequence smoothes the sample path. This is due to an attenuation of the higher frequencies which is visible in the form of the spectral density in the right panel of Figure 4.3. With the contents of this Section, it has so far been established that the spectral density $f(\omega)$ is a population quantity describing the impact of the various periodic components.
