View the step-by-step solution to:

# Problem 3.2 Let H E RM" be symmetric and idempotent, hence a projection matrix. Let a: N N (0, In). (a) Let a &gt; 0 be a positive number. Find the

Problem 3.2 Let H ∈ R n×n be symmetric and idempotent, hence a projection matrix. Let x ∼ N(0, In). (a) Let σ > 0 be a positive number. Find the distribution of σx. (b) Let u = Hx and v = (I − H)x and find the joint distribution of (u, v). 1 (c) Someone claims that u and v are independent. Is that true? (d) Let µ ∈ Im(H). Show that Hµ = µ. (e) Assume that 1 ∈ Im(H) and find the distribution of 1 T Hx. Here, 1 = (1, . . . , 1) ∈ R n is the vector of all ones.

Problem 3.2 Let H E RM” be symmetric and idempotent, hence a projection matrix. Let
a: N N (0, In). (a) Let a &gt; 0 be a positive number. Find the distribution of (79:. (b) Let a = H2: and v = (I — H )2: and ﬁnd the joint distribution of (a, v). (c) Someone claims that u and v are independent. Is that true?
(d) Let p E Im(H). Show that H pi = p. (e) Assume that 1 E Im(H) and ﬁnd the distribution of 1TH27. Here, 1 =
(1, . . . ,1) 6 IR” is the vector of all ones.

### Why Join Course Hero?

Course Hero has all the homework and study help you need to succeed! We’ve got course-specific notes, study guides, and practice tests along with expert tutors.

### -

Educational Resources
• ### -

Study Documents

Find the best study resources around, tagged to your specific courses. Share your own to gain free Course Hero access.

Browse Documents