I cannot figure out how to do standard deviation. standard deviation 2, 5, 47, 11, 13, 48, 39, 36
2-25.125=-23.125 = 534.77
5-25.125=-20.125 = 405.02
47-25.125=21.875 = 478.52
11-25.125=-14.125 = 199.52
13-25.125=-12.125 = 147.02
48-25.125=22.875 = 523.27
39-25.125=13.875 = 192.52
36-25.125=10.875 = 118.27
Sum 2598.41
If I divide by one less,which I am supposed to do I think, I get 371.20 sqrt= 19.27
If I divide by 8 I get 324.80 sqrt=18.02
The possible answers are: A) 24.5 B) 324.9 C) 18 D) 25.1
I checked all your calculations and found no errors.
(although you wrote your solutions with incorrect use of the "equal' sign)
Here is a webpage, by Wolfram a dependable source,
which explains the difference in the two methods of finding standard deviation.
Check with your text or your instructor whether you divide by N or N-1 .
I also got 19.27 after dividing by 7 and
18.02 after dividing by 8, so I don't know where they get your answers.
oops
forgot to post the webpage.
http://mathworld.wolfram.com/StandardDeviation.html
To calculate the standard deviation for a set of numbers, you can follow these steps:
1. Find the mean (average) of the numbers. Add up all the numbers and divide by the total count. For example, for the given set:
(2 + 5 + 47 + 11 + 13 + 48 + 39 + 36) / 8 = 201 / 8 = 25.125
2. Subtract the mean from each number and square the result. This gives you the squared differences from the mean. For example:
(2 - 25.125)^2 = 529.640625
(5 - 25.125)^2 = 399.015625
(47 - 25.125)^2 = 474.515625
(11 - 25.125)^2 = 198.890625
(13 - 25.125)^2 = 147.390625
(48 - 25.125)^2 = 520.765625
(39 - 25.125)^2 = 192.890625
(36 - 25.125)^2 = 117.015625
3. Find the average of these squared differences. Sum all the squared differences and divide by the total count. For example:
(529.640625 + 399.015625 + 474.515625 + 198.890625 + 147.390625 + 520.765625 + 192.890625 + 117.015625) / 8 = 2579.125 / 8 = 322.390625
4. Take the square root of the result from step 3. This gives you the standard deviation. For example:
√322.390625 = 17.962632
Therefore, the standard deviation for the given set of numbers (2, 5, 47, 11, 13, 48, 39, 36) is approximately 17.96.