Standard Deviation

SYLT

Can somebody explain standard deviation to me?

Q7. Paper 2. 2004.

The mean of the set of numbers (1, 3, 7, 9) is 5.

Find the standard deviation, correct to one decimal place.

_______

Junco Partner

enter the code of the question onto e-xamit.ie and it'll run through the question step by step

MaggieNF

i have that done, i can scan it in and send it to you

SYLT

f0ggy92 wrote: »

enter the code of the question onto e-xamit.ie and it'll run through the question step by step

Folens papers

MaggieNF wrote: »

i have that done, i can scan it in and send it to you

That would be tops.

JoeyBuddy

You go through the numbers and take them away from 5.
(5-1=4, 5-3=2, 7-5=2 etc...)

Then you get 4,2,2,4.
Get the squares of all of them.
= 16,4,4,16
Add them together.
You get 40

Put 40 over the number of numbers. (4)
And get the square root of that.

The answer is square root of 40/4

If I'm not mistaken. Double check that though.

mick_jt

http://www.examinations.ie/archive/markingschemes/2004/LC003GLP1EV.pdf

Its all on examinations.ie in material archive.

The solution you want is on page seventy of the above link.

MyHair

f0ggy92 wrote: »

enter the code of the question onto e-xamit.ie and it'll run through the question step by step

Examit.ie is down >_<
What a time to be down too!

Burswood

MyHair wrote: »

Examit.ie is down >_<
What a time to be down too!

Checked @ 21:40. Its up.

Junco Partner

MyHair wrote: »

Examit.ie is down >_<
What a time to be down too!

probably cant handle the amount of traffic it's getting

Kylzer911

JoeyBuddy wrote: »

You go through the numbers and take them away from 5.
(5-1=4, 5-3=2, 7-5=2 etc...)

Then you get 4,2,2,4.
Get the squares of all of them.
= 16,4,4,16
Add them together.
You get 40

Put 40 over the number of numbers. (4)
And get the square root of that.

The answer is square root of 40/4

If I'm not mistaken. Double check that though.

i think it could be 5 from the other.. 1-5 =-4 etc..

i think.. :rolleyes:

eoins23456

square of all the numbers/number of numbers take away mean squared then the square root of ur answer

Duncannon

mick_jt wrote: »

http://www.examinations.ie/archive/markingschemes/2004/LC003GLP1EV.pdf

Its all on examinations.ie in material archive.

The solution you want is on page seventy of the above link.

The quick way for the standard deviation is the mean of the squares - square of the mean you can find it on the 2fm 0906 site

Mwah

Kylzer911 wrote: »

i think it could be 5 from the other.. 1-5 =-4 etc..

i think.. :rolleyes:

yeah your right
im so glad that came up