Back
to top
Maths Sample Moments Question
Watch
Announcements
Page 1 of 1
Go to first unread
Skip to page:
Prove the following identities:
(m'k = raw sample moment, mk = central sample moment)
![Name: 2020-11-25 (2).png
Views: 11
Size: 10.1 KB]()
(m'k = raw sample moment, mk = central sample moment)
0
reply
Report
#2
They're fairly well known - have you looked at your notes/googled?
If you have a problem, can you post the full question (is this UG?) and what you've tried/describe what problem you're having.
If you have a problem, can you post the full question (is this UG?) and what you've tried/describe what problem you're having.
Last edited by mqb2766; 1 month ago
0
reply
(Original post by mqb2766)
They're fairly well known - have you looked at your notes/googled?
If you have a problem, can you post the full question (is this UG?) and what you've tried/describe what problem you're having.
They're fairly well known - have you looked at your notes/googled?
If you have a problem, can you post the full question (is this UG?) and what you've tried/describe what problem you're having.
0
reply
Report
#4
(Original post by SuprDooprPoopr)
I'm UG, simply I want to try and prove them, but I'm not sure how to.
I'm UG, simply I want to try and prove them, but I'm not sure how to.
0
reply
(Original post by mqb2766)
So you have notes, what have you covered? Also, can you upload the full question pls?
So you have notes, what have you covered? Also, can you upload the full question pls?
edit: sorry I don't know how to do symbols of sums etc
0
reply
Report
#6
(Original post by SuprDooprPoopr)
The full question is just "Prove the following identities" and thats what I need to prove. I know that the raw sample moment is m'k = 1/n (sum Xi^k) and the central sample moment is mk = 1/n (sum (Xi-Xbar)^k). I've seen the identities on the internet but they all just say the answer and I'm not sure how they actually get to that answer.
edit: sorry I don't know how to do symbols of sums etc
The full question is just "Prove the following identities" and thats what I need to prove. I know that the raw sample moment is m'k = 1/n (sum Xi^k) and the central sample moment is mk = 1/n (sum (Xi-Xbar)^k). I've seen the identities on the internet but they all just say the answer and I'm not sure how they actually get to that answer.
edit: sorry I don't know how to do symbols of sums etc
Have you been tried the first one? It's actually hard not to get it correct. Upload what you've tried?
Last edited by mqb2766; 1 month ago
0
reply
(Original post by mqb2766)
The first two parts are easily available, they were top of the list when I googled (to check) last night. But it's generally good to prove the simpler ones yourself. It's also good to upload a pic of the actual question and any other relevant parts. Can you pls do it.
Have you been tried the first one? It's actually hard not to get it correct. Upload what you've tried?
The first two parts are easily available, they were top of the list when I googled (to check) last night. But it's generally good to prove the simpler ones yourself. It's also good to upload a pic of the actual question and any other relevant parts. Can you pls do it.
Have you been tried the first one? It's actually hard not to get it correct. Upload what you've tried?
This is what I have so far:
0
reply
Report
#8
(Original post by SuprDooprPoopr)
I don’t know what else of the question you want me to upload? That’s the whole question.
This is what I have so far:
![Name: 2B85670B-3A69-48D9-AA9C-CBD53CCF3638.jpeg
Views: 7
Size: 127.7 KB]()
I don’t know what else of the question you want me to upload? That’s the whole question.
This is what I have so far:
0
reply
Report
#9
(Original post by SuprDooprPoopr)
I don’t know what else of the question you want me to upload? That’s the whole question.
This is what I have so far:
![Name: 2B85670B-3A69-48D9-AA9C-CBD53CCF3638.jpeg
Views: 7
Size: 127.7 KB]()
I don’t know what else of the question you want me to upload? That’s the whole question.
This is what I have so far:
0
reply
0
reply
Report
#11
However it also seems to say this is your homework, so I guess you should do it.
0
reply
(Original post by mqb2766)
No. It helps to see the question and how things are defined.
However it also seems to say this is your homework, so I guess you should do it.
No. It helps to see the question and how things are defined.
However it also seems to say this is your homework, so I guess you should do it.
0
reply
Report
#13
(Original post by SuprDooprPoopr)
Obviously, but I want some help, as you should get help when you are struggling! You're clearly not going to help me, if your next message isn't helpful I'm not gonna bother.
Obviously, but I want some help, as you should get help when you are struggling! You're clearly not going to help me, if your next message isn't helpful I'm not gonna bother.
In your OP there is no indication of what you'd done/what problems you're actually having. Both things will get more informative responses quicker. A picture of the actual question helps as sometimes people don't give a full description. See the sticky at the top of the forum.
https://www.thestudentroom.co.uk/sho....php?t=4919248
Last edited by mqb2766; 1 month ago
0
reply
(Original post by mqb2766)
See the questions in #9.
In your OP there is no indication of what you'd done/what problems you're actually having. Both things will get more informative responses quicker. A picture of the actual question helps as sometimes people don't give a full description. See the sticky at the top of the forum.
https://www.thestudentroom.co.uk/sho....php?t=4919248
See the questions in #9.
In your OP there is no indication of what you'd done/what problems you're actually having. Both things will get more informative responses quicker. A picture of the actual question helps as sometimes people don't give a full description. See the sticky at the top of the forum.
https://www.thestudentroom.co.uk/sho....php?t=4919248
0
reply
Report
#15
(Original post by SuprDooprPoopr)
Obviously, but I want some help, as you should get help when you are struggling! You're clearly not going to help me, if your next message isn't helpful I'm not gonna bother.
Obviously, but I want some help, as you should get help when you are struggling! You're clearly not going to help me, if your next message isn't helpful I'm not gonna bother.
Rather than expanding out
(which is going to make things more complicated), you want to replace 
by (so things get *less* complicated).As far as a summation goes,
is a constant (it doesn't depend on i), so, for example, 
.Don't write "
because ..." unless the "..." is actually going to explain/prove why the statement is true. You've simply put down some definitions and substituted them into the problem. It's not clear if you think erroneously that this constitutes a proof, or you're just laying out some basic facts, but either way, that "because" is not justified and is confusing.For these problems, you're actually going to be better off starting from the definitions of [tex]m_1', m_2', m_3'[/tex and trying to get to the desired expressions, rather writing down both the starting point and ending point and trying to show they're equal (as you appear to be attempting).
0
reply
X
Page 1 of 1
Go to first unread
Skip to page:
Quick Reply
Today on TSR
-
Ofqual consultationTeachers to use 'mini-exams' and other work to decide grades
- Is it too late to do well in my A-levels?
- How are you feeling today?
- 2021 wellbeing blog launch
- Student tips on lockdown mental health