Consider 18x4y + 3x3y2 – 39x²y3 + 12x2y4 as an expression in x. xy
x^y
3x^2y
3xy

Part A
What is the greatest common factor (GCF) for the four terms?

Part B

what is the leading coefficient of the expression ?

3
4
12
8

Consider the linear model for a two-stage nested design with b nested in a as given below. yijk=\small \mu + \small \taui + \small \betaj(i) + \small \varepsilon(ij)k , for i=1,; j= ; k=1, assumption: \small \varepsilon(ij)k ~ iid n (0, \small \sigma2) ; \small \taui ~ iid n(0, \small \sigmat2 ); \tiny \sum_{j=1}^{b} \small \betaj(i) =0; \small \varepsilon(ij)k and \small \taui are independent. using only the given information, derive the least square estimator of \small \betaj(i) using the appropriate constraints (sum to zero constraints) and derive e(msb(a) ).