T2. Estimating a population mean An intercept-only model is an alternative way to express that univariate data form a random sample. Y], . . . , Y?\" 1151 f where f is any distribution with a nite mean and variance is equivalent to YiZM+Eia [i=15'uan with the standard model assumptions. i. Write the intercept-only model in matrix form. ii. Derive the least squares estimator of p: using the general OLS estimator (x' x)'1x' Y. iii. Consider estimating it using a weighted average: it = ital-Y:- where 210,; = 1 1'21 1; Is it possible that var