Question

What is the standard deviation of the following data set rounded to the nearest tenth?
60, 40, 35, 45, 39

Answer 1

What tools have you available?
What method have you at your disposal?

Answer 2

first find the mean then use the formula 1/n-1((xi -u)^2 +.... +(xn - u)^2)

Answer 3

u = mean, xi is u each data for x til ur last one. n= total sample

Answer 4

8.7

Answer 5

then u sqrt it, I forgot to mention that part

Answer 6

no 8.7 isn't right

Answer 7

what did u get for ur mean?

Answer 8

s^2 = sum (value - mean)^2 /(n-1) where n = number of samples

s = standard deviation

Answer 9

then i have been lied to http://www.mathsisfun.com/data/standard-deviation-calculator.html

Answer 10

@douglaswinslowcooper How do you know it's a sample?
@alexgriffin If only we could get a response from the OP.

Answer 11

"data set" suggested sample to me rather than being the entire population of interest

Answer 12

Not a standard definition. No real objection, though. If that's the whole population, why in the name of reason would we care about the standard deviation?

Answer 13

@tkhunny you seem to be very wise. Help me on my physics of you don't mind

Answer 14

sorry for the wait I got 43.8

Answer 15

43.8 is the Mean, or Average. That is not the question.

Answer 16

i was replying to @fiberdust

Answer 17

Ah. Missed that.

Very good. That is the Mean.
Not sure what else fiberdust is calculating. Rounding to integer, maybe?

Answer 18

if u don't get these numbers right you won't get the sd right

Answer 19

it's a very tedious process

Answer 20

sum/n = mean

Answer 21

see i used 45 twice

Answer 22

219/5

Answer 23

my bad

Answer 24

haha its okay :)

Answer 25

i had 44.8 cuz i used 45 instead of 40 mb

Answer 26

so yes 43.8 is correct mean

Answer 27

what i do from there

Answer 28

I might be wrong how i view this but maybe others can confirm or correct me. Since you are given data sample it's going to be 1/n-1 for your formula the other part of the formula is same you will use your data sample value for example (60- mean)^2 +... continue to do each data value then add them up then use 1/n-1( ) this will be s^2 which is your variance. square root the variance to get standard deviation

Answer 29

We are ASSUMING it's a SAMPLE. State that and use n-1 in the denominator.