Hi folks,
I plugged the following set of numbers into Excel:
[600 470 170 430 300]
I found the mean (394), summed the numbers, divided by 5 to get variance (21704). I then did the square root to find stdev (147.32).
Using Excel or Wolfram Alpha's variance and stdev function give me differnt numbers, variance 27130 and stdev 164.71 respectively. Why? I believe I am following the equation as listed on Wikipedia, my stat text book, and the following page:
http://www.mathsisfun.com/data/standard-deviation.html
What am I missing?
Thank you for any help you can give!