I need some serious help with maths!!!!?

Question

For my GCSE maths coursework, i was going to put in some standard deviation, now we have done this in class but it was a
while ago and i don't really understand it.
Please could you go through the process - the stages pf what you have to do - thankyou so much !!!

Answer 1

1. first get the average or mean of the set of numbers
ex. 1, 3, 5 ....average = 3
2. next subtract each number by the average
1 - 3 = -2
3 - 3 = 0
5 - 3 = 2
3. next square the results from #2
(-2) ^ 2 = 4
(0) ^ 2 = 0
(2) ^ 2 = 4
4. next add the results from #3
4 + 0 + 4 = 8
5. next divide the result from #4 by "the number of samples you have less 1" ....in case you don't know, you have 3 samples (1, 3, & 5)
= 8 / (3 - 1)
= 8 / 2
= 4
6. next square root the result from #5
sq rt of 4 = 2

2 is your standard deviation.

in case you observed, 2 is the usual difference of numbers from your average. in our simple example, we used 1, 3, and 5. 3 was the average. the usual difference of the other numbers from 3 was 2 which makes sense because our other two numbers are 3 and 5.

Answer 2

WOw... that is almost impossible to explain or diagram given the medium of this little box and the limited character set available.

its pretty easy tho.. mostly dog work.

Google Standard Deviation and you will find several excellent resources to walk you thru the calculations.