do acf pacf represent seasonality, trend what acf means in statistics what is acf in psychology what is parcf what does acf mean in apcf which of the following is an example of autocorrelation? what does pacf mean what is the purpose of acf and pacf what is the relationship between acf and pacf what is the relationship between acf and pacf do pacf and acf have a trend what is a acf and pacf in data analysis what is the meaning of the acf and pacf what is the difference between acf and pacf of y and residuals what does this mean when no seasonality of a graph is obtained? what is the difference between acf and pacf acf meaning what acf means how to use apcf data what is acf in a graph