MathAnswer included
posted by Anonymous .
{9, 7, 13, 24, 32, 45, 47}
First you have to find the mean
The mean is
9+7+13+24+32+45+47=177/7=25.2857=25.29
Find the standard deviation for the given data. Round your answer to one more decimal place than the original data.
{9, 7, 13, 24, 32, 45, 47}
(25.299)^2=16.29^2=265.36
(25.297)^2=18.29^2=334.52
(25.2913)^2=12.29^2=151.04
(25.2924)^2=1.29^2=1.66
(25.2945)^2= 19.71^2=388.48
(25.2947)^2= 21.41^2=458.39
1599.45
Sqrt 39.99
My answer isn't matching the possible choices

your mean is correct.
(25.299)^2=16.29^2=265.36
(25.297)^2=18.29^2=334.52
(25.2913)^2=12.29^2=151.04
(25.2924)^2=1.29^2=1.66
(25.2945)^2= 19.71^2=388.48
(25.2947)^2= 21.41^2=458.39
Your second moment about the mean is correct.
Now, standard deviation. I would divide that sum by n=7 (or in real life, n1) then take the square root.
I get about 16
http://hubpages.com/hub/deviation