You are Here: Home >< Maths

# Standard Deviation Watch

1. Just to be sure, is this the correct method of finding standard deviation from ungrouped data:

Thanks.
2. (Original post by Abdul-Karim)
Just to be sure, is this the correct method of finding standard deviation from ungrouped data:

Thanks.
I know nothing about spread sheets but by trying to read waht is going on I am assuming you are trying to find the standard deviation of 12 numbers

3. (Original post by TeeEm)
I know nothing about spread sheets but by trying to read waht is going on I am assuming you are trying to find the standard deviation of 12 numbers

Correct, could you point me in the right direction.

From my understanding, I found the variance = (SumOf(frequency-mean)^2)/SumOfFrequency

I don't know the keyboard codes for them ^ and then the standard deviation is simply the square root of that??

Btw I've rounded the mean to the nearest integer, for simplification purposes.
4. (Original post by Abdul-Karim)
Correct, could you point me in the right direction.

From my understanding, I found the variance = (SumOf(frequency-mean)^2)/SumOfFrequency

I don't know the keyboard codes for them ^ and then the standard deviation is simply the square root of that??

Btw I've rounded the mean to the nearest integer, for simplification purposes.
i only see 12 numbers ...

what is the sum of frequency?
5. (Original post by TeeEm)
i only see 12 numbers ...

what is the sum of frequency?
I would assume it's the sum of all the test scores, is it not?

Or am I meant to divide by the sum of observations? which would be 12.
6. (Original post by Abdul-Karim)
I would assume it's the sum of all the test scores, is it not?

Or am I meant to divide by the sum of observations? which would be 12.
I have no idea what the question is ...

I am trying to decipher it by looking to the spreadsheet.

If I am assuming the right things the variance is 2621/12
7. i checked using an online calculator ?

8. (Original post by the bear)
i checked using an online calculator ?

Yeah I got it, thanks.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 27, 2015
Today on TSR

What should I do?

### How to go from a 4 to a 9 in GCSE Maths

Discussions on TSR

• Latest
• ## 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.

• Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## 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.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE