... modelyt - "yt-1 = $0(1 - ") + $1(x1t - "x1t-1) + + $p(xpt - "xpt-1) + ,t - ",t-1orzt = ( + $1v1t + + $pvpt + ut,where zt = yt - "yt-1, ... pairwise observations, n i - 1 S = 3 3 sign(xi - xj), (8.14) i = 2 j = 1 where sign(z) is -1 for z < 0, 0 for z = 0, and +1 for z > 0. For a seriesof values in a random order the expected ... autoregressive-moving average (ARMA) models combine thefeatures of equations (8.17) and (8.18). Thus a ARMA(p,q) model takesthe formxt = µ + "1(xt-1 - µ) + + "p(xt-p - µ) + $1zt-1...