4) Apply a moving average lter to Y1, where Y1 is the natural logarithm of the Johnson and Johnson earnings data (the original data are given in the j j object in the astsa package}. Specifically, let Vt: (Yr + Y1 1+ 1'1. 2 + Yr. 3);\"4. The R code v = filterly, rep(l/4, 4), sides = 1) may be helpful in implementing this. Type help (f i lter) in R for more details about this R function. Plot Y1 as a line and overlay (superimpose) Vt as a dashed line, and provide this plot. Discuss whether the moving average lter captures the overall trend in the time series