' I Consider the following geostatistical model Z(si) = ,u + U(s,-) + 14.9,), i: 1, . . . ,n. Here, U(s) is a Spatial process with mean zero and covariance function Cum) = 02 exp {g }, where 02 is the partial sill parameter, and q is the range parameter. Moreover, 1/(31), . . . ,v(sn) is a sequence of independently and identically distributed Gaussian random variable N (0, 72), where 72 is the nugget effect. Furthermore, U(3) and 1/(3) are independent of each other. Let E be the covariance matrix of Z, where Z = (Z(sl), . . .,Z(sn))T. Suppose n = 3 and 3,- =21 (a Write down the covariance function of Z (s). (b Write down 2 in term of (02, T2, gt). ((1 Let a = 02 +72, b = 72/0,, write down 2 in term of (a, b, (15). BE 32 ) l (0) Calculate 33:, 3112; and (3%. l (e) Let a = 02 +72, b = 72/0,, calculate E9 E and 62