What is Chebyshev's Inequity and How can it Solve Probabilities?

  • Thread starter Thread starter freezer
  • Start date Start date
Click For Summary

Homework Help Overview

The discussion revolves around applying Chebyshev's inequality to a random variable X with an unknown distribution, where the mean (μ) is 10 and the variance (σ²) is 1.2. Participants are tasked with finding upper bounds on the probabilities of deviations from the mean for various values, as well as plotting these bounds and determining specific deviation values for a given probability threshold.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants express confusion regarding the application of Chebyshev's inequality, particularly due to missing lecture content and the lack of relevant textbook material. There are inquiries about how to approach the problem and the necessity of understanding the distribution type for finding bounds.

Discussion Status

Some participants are seeking guidance and resources to better understand Chebyshev's inequality and its application to the problem. Others have suggested looking for online resources, while some express frustration with the responses received. There appears to be a mix of interpretations regarding the best approach to the problem.

Contextual Notes

Participants note the absence of direct instruction and relevant resources, leading to challenges in applying the concepts effectively. There is also mention of a specific source that may provide the necessary equations for certain parts of the problem.

freezer
Messages
75
Reaction score
0

Homework Statement


The random variable X has an unknown distribution with μ = 10 and σ^2 = 1.2. use Chebyshev's inequity to solve the following.

a) Find an upper bound on the probability that X deviates from its mean by at least 2
b) Find an upper bound on the probability that X deviates from its mean by at least 100.
c) Let D be the amount of deviation from the mean on X, and plot the bound values given by Chebyshev's inequity for 0 < D < 1000. Use a log scale on the y-axis.
d) What does D have to be to guarantee an upper bound of exactly 10^(-6) with Chebyshev's inequity?


Homework Equations





The Attempt at a Solution



I missed lecture the day this was presented and the subject is not in the textbook. I have watched several videos on the concept but they do not seem relevant to this question. I have read a few .edu sites on the matter but seem to be more about the k value. So my professor is out of town till and won't be back before this is due. Can someone give me some guidance on this problem?
 
Physics news on Phys.org
freezer said:

Homework Statement


The random variable X has an unknown distribution with μ = 10 and σ^2 = 1.2. use Chebyshev's inequity to solve the following.

a) Find an upper bound on the probability that X deviates from its mean by at least 2
b) Find an upper bound on the probability that X deviates from its mean by at least 100.
c) Let D be the amount of deviation from the mean on X, and plot the bound values given by Chebyshev's inequity for 0 < D < 1000. Use a log scale on the y-axis.
d) What does D have to be to guarantee an upper bound of exactly 10^(-6) with Chebyshev's inequity?


Homework Equations





The Attempt at a Solution



I missed lecture the day this was presented and the subject is not in the textbook. I have watched several videos on the concept but they do not seem relevant to this question. I have read a few .edu sites on the matter but seem to be more about the k value. So my professor is out of town till and won't be back before this is due. Can someone give me some guidance on this problem?

Show your work. I cannot believe you can do absolutely nothing with any of this problem. There are loads of websites available that go through this material, some in great detail and with worked examples.
 
Ray Vickson said:
Show your work. I cannot believe you can do absolutely nothing with any of this problem. There are loads of websites available that go through this material, some in great detail and with worked examples.

Ray,

I understand that some tutors get a rush when they get the opportunity to denigrate a student and pump-up their own ego through condescending remarks that serve little purpose. Hopefully, I have given you the opportunity to get that off your chest. Now that we are past that, I am not asking for you to give me the answer to the problem. However, a link would be helpful to one of the "loads of websites" that you found that would provide me guidance on how to solve this problem would be appreciated. The multitude of sites I have explored have not presented the needed information, or at least in a manner I find relevant to this problem.

Thank you for your generous help,
Rod
 
Hi freezer. I just googled Chebyshev's inequality and I see lots of resources. I don't find Ray's post to be egotistical, I think he's just trying to help you help yourself rather than help you out right... which is to your benefit in the long term.
 
Pythagorean said:
Hi freezer. I just googled Chebyshev's inequality and I see lots of resources. I don't find Ray's post to be egotistical, I think he's just trying to help you help yourself rather than help you out right... which is to your benefit in the long term.

Pythagorean,

Thanks for your reply. I to googled the key word but was more overwhelmed with the information and was having trouble applying it to this particular problem. I was looking at this source:

"www.ams.sunysb.edu/~jsbm/courses/311/cheby.pdf"

I was thinking it would be one sided setup. However, it seems to find the bounds, you need to know the type of distribution.
 
Last edited by a moderator:
freezer said:
Pythagorean,

Thanks for your reply. I to googled the key word but was more overwhelmed with the information and was having trouble applying it to this particular problem. I was looking at this source:

"www.ams.sunysb.edu/~jsbm/courses/311/cheby.pdf"

I was thinking it would be one sided setup. However, it seems to find the bounds, you need to know the type of distribution.
freezer, the very first equation at that link gives you exactly what you need to answer (a) and (d) immediately. You don't need to read the rest of the text.
 
Last edited by a moderator:

Similar threads

  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
Replies
11
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K