Show that the estimators APR, AML, ARE, and AFH in Section 13.3 possess the following properties: (i)

Show that the estimators ˆAPR, ˆAML, ˆARE, and ˆAFH in Section 13.3 possess the following properties: (i) They are even functions of the data—that is, the estimators are unchanged when y is replaced by −y and (ii) they are translation invariant—that is, the estimators are unchanged when y is replaced by y + Xb for any b ∈ Rp.