Question

I need help finding the variance and the standard deviation of some values. Can someone please take me through it?

Answer 1

Round to the nearest tenth.

Find the mean, variance, & standard deviation of these values:

Answer 2

1,3,11,11,11,11

Answer 3

@doc.brown can you help?

Answer 4

Mean= average.
What's the average?

Answer 5

1+3 + 11+11+11+11 = 48/ 6 = 8

Mean = 8

Answer 6

I need help in the variance and standard deviation

Answer 7

Variance is the average of the squares of the difference.

Answer 8

11-8 ^2 like that?

Answer 9

So, find out how far each value is from the mean.
1 is 8-1 so 7 away from the mean
3 is 8-3 = 5 etc

Answer 10

11 - 8

or 8 - 11

for the 11's?

Answer 11

11-8

Answer 12

11-8=3
11-8=3
11-8 =3
11- 8 = 3
8-1 = 7
8-3 =5

Answer 13

what's next?

Answer 14

Square them all, then find the average.

Answer 15

3^2 = 9
3^2 = 9
3^2 = 9
3^2 = 9
7^2 = 49
5^2 = 25

Answer 16

9*4 + 25+49 = 110/ 6 = 18.3

Answer 17

thats the variance correct?

Answer 18

That's the variance. 18.3
I can go over why it gets squared if you'd like.
But for now take the square root of that for the Standard Deviation.

Answer 19

sqrt 18.3 = 4.278

Answer 20

So the Standard Deviation is 4.3
Which makes sense, your data values are basically 8.0\(\pm\)4.3

Answer 21

which equals 4.3

Answer 22

oh my thank you for taking your time to help me and everything!

Answer 23

No prob

Answer 24

Just to make sure

mean: 8
Variance: 18.3
Standard deviation: 4.3

Answer 25

correct?

Answer 26

Round to the nearest tenth.
8.0

Answer 27

for the mean?

Answer 28

Yeah, it's a good habit and will save you marks later in life.
Mean: 8.0
Variance: 18.3
Standard deviation: 4.3