Solved:Fit an AR(1) to xt using maximum likelihood (basically unconditional least squares) as in Section 3.6. The easiest way to do this is to use sarima from astsa. Comment on the significance of the regression parameter estimates of the model. What is the estimate of the white noise variance.

 ARIMA models (including improved diagnostics) in a short command. It can also be used to perform regression with autocorrelated errors. This is a front end to arima () with a different back door.  

Usage Regression coefficients represent the mean change in the response variable for one unit of change in the predictor variable while holding other predictors in the model constant. .

Explanation: White noise refers to a statistical model for signals and signal sources, rather than to any specific signal. White noise draws its name from white light.

new communications technology has affected the way social movements are organized because nowadays, social movements rely on social networks and the media to get different people with a similar way of thinking in contact, and thus, get them to mobilize for a greater cause.

individuals only participate in collective action when they feel identified with it. is in this aspect that social media becomes relevant, because it guarantees communication among all individuals and organizes the social actions that are going to be carried out, i.e., the social movements.

in addition, being covered by the media is important to validate the message and make it relevant in the social agenda, as well as to reach more people who can share interests, appealing to public sympathy for their cause.

in conclusion, it is by social networks and social media that social movement is given birth; by connecting different individuals with similar ideas and organizing them to mobilize for a greater cause.