Difference between the sum of squared deviations and standard deviation?

Watch
kenrepjm
Badges: 11
Rep:
?
#1
Report Thread starter 3 weeks ago
#1
I was watching a video and for both they said they show the average distance from the mean, but how when they have different formulas?
0
reply
ghostwalker
  • Study Helper
Badges: 17
?
#2
Report 3 weeks ago
#2
(Original post by kenrepjm)
I was watching a video and for both they said they show the average distance from the mean, but how when they have different formulas?
Neither of them show the average distance from the mean: Assuming this is A-level, you're unlikely to be dealing with the average distance from the mean, which has a different formula to the standard deviation.

The "standard deviation" is a measurement of spread about the mean, and in that regard it's akin to, but not the same as, the average distance from the mean.

The "sum of squared deviations" is just that, a sum, not an average; although it is used in the calculation of the standard deviation.
0
reply
kenrepjm
Badges: 11
Rep:
?
#3
Report Thread starter 3 weeks ago
#3
(Original post by ghostwalker)
Neither of them show the average distance from the mean: Assuming this is A-level, you're unlikely to be dealing with the average distance from the mean, which has a different formula to the standard deviation.

The "standard deviation" is a measurement of spread about the mean, and in that regard it's akin to, but not the same as, the average distance from the mean.

The "sum of squared deviations" is just that, a sum, not an average; although it is used in the calculation of the standard deviation.
Thanks! I'm not sure if I'll be asked this in A Level but assuming I'm asked what is the average distance from the mean (in order to find outliers) would I use standard deviation?
0
reply
ghostwalker
  • Study Helper
Badges: 17
?
#4
Report 3 weeks ago
#4
(Original post by kenrepjm)
Thanks! I'm not sure if I'll be asked this in A Level but assuming I'm asked what is the average distance from the mean (in order to find outliers) would I use standard deviation?
If you're looking for outliers you would look from those data points beyond a certain number of standard deviations from the mean.

The term "average distance from the mean" shouldn't come up.
1
reply
kenrepjm
Badges: 11
Rep:
?
#5
Report Thread starter 3 weeks ago
#5
(Original post by ghostwalker)
If you're looking for outliers you would look from those data points beyond a certain number of standard deviations from the mean.

The term "average distance from the mean" shouldn't come up.
Thank you!
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Have you made your mind up on your five uni choices?

Yes, and I've sent off my application! (153)
54.64%
I've made my choices but havent sent my application yet (41)
14.64%
I've got a good idea about the choices I want to make (31)
11.07%
I'm researching but still not sure which universities I want to apply to (26)
9.29%
I haven't started researching yet (16)
5.71%
Something else (let us know in the thread!) (13)
4.64%

Watched Threads

View All