Consider the population model y = x + u E(u|x) = 0, where the 1 (k

Consider the population model

y = xβ + u

E(u|x) = 0,

where the 1 × (k + 1) vector x is

x = (1, x₁, x₂, . . . , x_k).

Let {(x_i,y_i): i = 1, 2, . . . , n} be a random sample. Show that Assumptions E.3 and E.5 hold.