Question

whats the standard deviation of 34    66    42    68    30    42    43    36    63    37    37

Answer 1

First, sum the data: 498, then divide by the number of data=498/11=45.27 approx. This is the mean.

Next, we need to subtract the mean from each of the data and square it:

-124/11 127.0744

228/11 429.6198

-36/11 10.7107

250/11 516.5289

-168/11 233.2562

-36/11 10.7107

-25/11 5.1653

-102/11 85.9835

195/11 314.2562

-91/11 68.4380

-91/11 68.4380

Now we add up the squares: 1870.1818 and divide by 11=170.0165. This is the variance and the SD is the square root=13.04.