Question

What is the variance of the data set?
63 54 62 59 52

(Points : 1)
11.6

14.5

18.8

23.5

Answer 1

@rishavraj

Answer 2

id subtract 52 from them all and then work it .. if i had to do it by hand

Answer 3

hmmmmm u know how to calculate the variance....
u need to find the average of the numbers first

Answer 4

i dont know how to calculate the variance

Answer 5

63 54 62 59 52
11 2 10 7 0

subtract another 6

5 -4 4 1 -6

this set is simpler to work by hand, and has the same variance

Answer 6

i guess 57 was the mean of the larger set, cause its 0 now

Answer 7

Why 6? I still am entirely confused

Answer 8

\[mean = \frac{ 63 + 54 + 62 + 59 + 52 }{ 5 }\]

Answer 9

all i did was shift the data set to smaller values, the varaince doesnt change since we still have the same internal measures

Answer 10

mean was 58

now, variance is determined by subtracting the mean from the data points anyways, to zero things out.

Answer 11

i just happened to get it zeroed out on a whim :)

take the average of the squared results

Answer 12

5 -4 4 1 -6 square these out?

Answer 13

yep

Answer 14

we would have subtracted the mean of that smaller set from its values, but the mean just happened to be 0 ... soo, square, sum, divide by 5

Answer 15

@LeilaJudeh http://www.mathsisfun.com/data/standard-deviation.html

Answer 16

2.23 -2 2 1 -2.44 ?

Answer 17

not sqrt, squares

Answer 18

25 16 16 1 36

Answer 19

-_- pardon my stupidity.

So now I add em up and divide by 5 right?

Answer 20

variance is calcualted as the average of the squared differences from the mean.

sum of [x-mean]^2 divided by the number of datapoints

yes, add them up and divide by 5

Answer 21

18.8

Answer 22

yep

Answer 23

X = (Xi........ mean.........Xf)

subtract the mean from the set of X

X-mean = (Xi-mean........ 0.........Xf-mean)

we have zeroed the set, square the differences from the mean and take their average

Answer 24

if we do this by hand, the sooner we can get the set near its zeroed mark, the simpler the calculations will be.

Answer 25

otherwise, stick them in the stats calculator and hit a button :)

Answer 26

as an aside, spose we got it down to this:

6 -3 5 2 -5

the mean is 5/5 = 1 we would subtract 1 from the set, and then square add average