Open study

is now brainly

With Brainly you can:

  • Get homework help from millions of students and moderators
  • Learn how to solve problems with step-by-step explanations
  • Share your knowledge and earn points by helping other students
  • Learn anywhere, anytime with the Brainly app!

A community for students.

Okay, I have another one here: Suppose that X1,...,X100 are random variables with E(Xi)=100,E(X2i)=10100 If Cov(Xi,Xj)=−1,i≠j what is Var(S), where S=∑i=1100Xi ? I got Var(S) to be 100, which is the correct answer but what good does knowing the covariance do? I tried using it, and it just throws everything off.

Statistics
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.

Get this expert

answer on brainly

SEE EXPERT ANSWER

Get your free account and access expert answers to this and thousands of other questions

what does mean E(X2i) means E(even) ?
It means \[E(X _{i}^{2})\] Sorry about the notation - it didn't copy and paste correctly.
oh got

Not the answer you are looking for?

Search for more explanations.

Ask your own question

Other answers:

so S is sigma(i)=1100Xi is it right
|dw:1392444372176:dw|
but it is not the answer because the problem wants var(s) but i dont know what is exact s?
Sorry, \[S=\sum_{i=1}^{100}X _{i}\]
|dw:1392445311784:dw|
|dw:1392445440041:dw|
|dw:1392445541588:dw|
I can't see the right side of what you did.
How'd you get n^2-n?
|dw:1392447809874:dw| How'd you get this part?
all is n^2 so you have to subtract from n (x1 x2 .. xn)
all term in sigma without itself terms
Suppose that (X,Y) is uniformly chosen from the set given by \[0

Not the answer you are looking for?

Search for more explanations.

Ask your own question