How do I find a variance for a set of numbers {1,16,8,17,12}

I got that variance-34.2, but I'm unsure. Any help? Thanks.

look at his page.

http://davidmlane.com/hyperstat/A16252.html

I looked at that page and did my problem according to the example, but the answer I got wasn't even a choice. Can you help al ittle more please?

did you get a mean of 10.8 ?

My squared differences were:
96.04, 27.04,7.84,38.44,1.44

that sum/5 = 34.16 which is the variance^2
so the variance = √34.16 = 5.845

notice that there is difference in the calculation depending on whether you divide by N or N-1.
Your text or your course should tell you which method to use.

No. I thought mean was adding up the numbers and then dividing by how many numbers.

So .51+.44+.04+.01=1 divided by 4=.25

(1 + 16 + 8 + 17 + 12)/5 = 10.8

mmmmh?

where did you get your numbers from ????

To find the variance of a set of numbers, you need to follow these steps:

1. Calculate the mean (average) of the numbers in the set.
To find the mean, add up all the numbers in the set, and then divide the sum by the total number of values in the set. For example:
Sum = 1 + 16 + 8 + 17 + 12 = 54
Mean = Sum / 5 = 54 / 5 = 10.8

2. Calculate the difference between each number in the set and the mean.
For each number in the set, subtract the mean from it. For example:
1 - 10.8 = -9.8
16 - 10.8 = 5.2
8 - 10.8 = -2.8
17 - 10.8 = 6.2
12 - 10.8 = 1.2

3. Square each of the differences from step 2.
Square each of the differences obtained in step 2. For example:
(-9.8)^2 = 96.04
(5.2)^2 = 27.04
(-2.8)^2 = 7.84
(6.2)^2 = 38.44
(1.2)^2 = 1.44

4. Find the sum of the squared differences from step 3.
Add up all the squared differences obtained in step 3. For example:
Sum of squared differences = 96.04 + 27.04 + 7.84 + 38.44 + 1.44 = 170.8

5. Calculate the variance.
To find the variance, divide the sum of squared differences from step 4 by the total number of values in the set. For example:
Variance = Sum of squared differences / Total number of values
Variance = 170.8 / 5 = 34.16

Therefore, the variance of the set {1, 16, 8, 17, 12} is approximately 34.16 (rounded to two decimal places). Based on your calculation of 34.2, it seems like you rounded it correctly to one decimal place. So, your answer of 34.2 is close enough.