Problem 3: Checking the Markov property
For each one of the following definitions of the state Xk at time k (for k=1,2,…), determine whether the Markov property is satisfied by the sequence X1,X2,….
A fair six-sided die (with sides labelled 1,2,…,6) is rolled repeatedly and independently.
(a) Let Xk denote the largest number obtained in the first k rolls. Does the sequence X1,X2,… satisfy the Markov property?
Yes - correct
(b) Let Xk denote the number of 6's obtained in the first k rolls, up to a maximum of ten. (That is, if ten or more 6's are obtained in the first k rolls, then Xk=10.) Does the sequence X1,X2,… satisfy the Markov property?
Yes - correct
(c) Let Yk denote the result of the kth roll. Let X1=Y1, and for k≥2, let Xk=Yk+Yk−1. Does the sequence X1,X2,… satisfy the Markov property?
No - correct
(d) Let Yk=1 if the kth roll results in an odd number; and Yk=0 otherwise. Let X1=Y1, and for k≥2, let Xk=Yk⋅Xk−1. Does the sequence X1,X2,… satisfy the Markov property?
Yes - correct
Let Yk be the state of some Markov chain at time k (i.e., it is known that the sequence Y1,Y2,… satisfies the Markov property).
(a) For a fixed integer r>0, let Xk=Yr+k. Does the sequence X1,X2,… satisfy the Markov property?
Yes - correct
(b) Let Xk=Y2k. Does the sequence X1,X2,… satisfy the Markov property?
Yes - correct
(c) Let Xk=(Yk,Yk+1). Does the sequence X1,X2,… satisfy the Markov property?
Yes - correct
"answered in full"
2 answers
Belonging to this very same problem set....
1.a. False
1.b. False
2.a. False
2.b. False
3.a. True
3.b. True
a - yes
b- yes
c - no
d- yes
2-
yes for all