Posted by LUA on .
Calculate the standard deviation for the following yields of corn: 142, 161, 132, 143, 147, 145, 146, and 152 bu/ac.
Are all yields obtained within one standard deviation of the mean?

math: standard deviation 
PsyDAG,
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you.
Again, here is what to do. We are not here to do all the work for you. Although it might take more effort to do the work on your own, you will profit more from your effort. We will be happy to evaluate your work though.
Find the mean first = sum of scores/number of scores
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation = square root of variance
I'll let you do the calculations.
Also see your previous post.