shirobia
shirobia
  • Threads: 3
  • Posts: 8
Joined: Sep 15, 2011
October 9th, 2011 at 12:00:51 AM permalink
Q1 Let (X_n) for n>0 be a Galton-Watson branching process starting with one particle (that is, X_0 = 1) and o ffspring distribution

p0 = 1/6 ; p1 = 1/3 ; p2 = 1/3 ; p3 = 1/6 ;

(A) P[lim n->infinity, X_n = 0] > 0
(B) P[lim n->infinity, Xn = infinity] > 0
(C) EX_n < EX_n-1
(D) P[Popul. ever dies out] = 0.5*sqrt(13) - (3/2)
(E) E(X_10) approx= 62:125
(F) Var(X_10) approx= 128.831...



Q2 Let (X_n), for n>0 be a Galton-Watson branching process starting with one particle (that is, X_0 = 1) and o ffspring distribution

p_k =(lamda^k)*exp(-lamda)/ (k!) ; k >= 0; 0 < k < 1;

(A) P[lim n->infinity, X_n = 0] < 1
(B) P[lim n->infinity, Xn = infinity] = 0
(C) EX_n < EX_n-1
(D) 0 is transient
(E) E(Xn) = lamda^n
(F) Var(Xn) = (lamda^n)*(sigma^2)


Thank you soo much!
Wizard
Administrator
Wizard
  • Threads: 1518
  • Posts: 27036
Joined: Oct 14, 2009
October 9th, 2011 at 12:45:22 AM permalink
We certainly get the gamut of questions here, from cheating boyfriends to Galton-Watson branching processes. To be honest with you, I don't know what that is. Hopefully ME or CM can be of more help.
"For with much wisdom comes much sorrow." -- Ecclesiastes 1:18 (NIV)
CrystalMath
CrystalMath
  • Threads: 8
  • Posts: 1911
Joined: May 10, 2011
October 9th, 2011 at 7:31:27 AM permalink
Is this True/False or do you pick an answer A to F? Some of the statements in A-F are clearly wrong given the info stated in Q1.
I heart Crystal Math.
buzzpaff
buzzpaff
  • Threads: 112
  • Posts: 5328
Joined: Mar 8, 2011
October 9th, 2011 at 8:25:42 AM permalink
The Galton–Watson process is a branching stochastic process arising from Francis Galton's statistical investigation of the extinction of family names.
shirobia
shirobia
  • Threads: 3
  • Posts: 8
Joined: Sep 15, 2011
October 9th, 2011 at 10:13:37 AM permalink
Quote: CrystalMath

Is this True/False or do you pick an answer A to F? Some of the statements in A-F are clearly wrong given the info stated in Q1.



pick an answer from A to F
CrystalMath
CrystalMath
  • Threads: 8
  • Posts: 1911
Joined: May 10, 2011
October 9th, 2011 at 5:17:25 PM permalink
Q1 Let (X_n) for n>0 be a Galton-Watson branching process starting with one particle (that is, X_0 = 1) and o ffspring distribution

p0 = 1/6 ; p1 = 1/3 ; p2 = 1/3 ; p3 = 1/6 ;

(A) P[lim n->infinity, X_n = 0] > 0
(B) P[lim n->infinity, Xn = infinity] > 0
(C) EX_n < EX_n-1
(D) P[Popul. ever dies out] = 0.5*sqrt(13) - (3/2)
(E) E(X_10) approx= 62:125
(F) Var(X_10) approx= 128.831...

C is false, since EX_n = EX_n-1 * 1.5 .
E is false, since EX_10 = 1.5^10 = 57.665 .

Tell us what you know, and maybe we can help more.
I heart Crystal Math.
  • Jump to: