prob & stats ques

[Sinistral]

[duck]

Hi.. :)

H) I think it should be none of the above.

4) Refer the following document.
http://economicsentrance.weebly.com/uploads/1/1/0/5/1105777/notes_1.pdf

[Ankit Agrawal]

1) Even i think it should be (d) None of the above. The answer is (w+z)/2.

2) Duck, Can you pin point the exact question in this document? I am unable to find it.

[duck]

Refer Page 5.

[Sinistral]

@ duck:

failed to load the document

[duck]

oh.. Please open Lessons
And refer Econ-sol

[Sinistral]

I think I am not able to understand the ques fully.
wrt the 3rd line "The expectation of the no. of observations in the sample that fall within a specified interval  [a,b]"

wrt the bold statement what I am understanding is:
suppose [a,b] ≡ [5,10]
then lets say the following values of (x1,x2) that lie in [5,10] (suppose) -- (5,6) , (7,8) , (9,10) , (7 , 7.5) , (5.5 , 6) , (5.6 , 8.7) . then the no. of observations in the sample is 6. Is this what the ques is trying to say?

Means the complete support of the rvs is {(x1,x2} : x1,x2 ∈ R}
given sample S is such that S= {(x1,x2): x1 ∈ [a,b] and x2 ∈ [a,b]}
and the no. of observations, N = card(S)

if yes, then why in soln N is only 0,1,2?

[duck]

The question is saying that X1 and X2 are two random variables and you draw one observation from X1 (say x1) and another from X2 (say x2). Now, you need to find the expectation of number of observations in the sample(which is (x1,x2) , it has only two values)) within a specified interval [a,b].

eg: you have drawn one sample as (2,3) and another sample as (3,5). Let [a,b]=[1,3] . Now, sample (2,3) has both observations lying in the interval and sample (3,5) has only one observation (3) lying in the interval.

[laracroft]

i think H should be option A ??

[Sinistral]

hi laracroft,

why option (a) i.e. 2(w+z) ??