Hi koan; Re: "I didn't say two SD deviations. I said 2+"; Actually, that's not -quite- what you said. At best it was what you *meant* to say.
Re: "... and an average of 2.5 SD. That is one in 500!"
In fact you never mentioned "2.5" anywhere in your post. Go back and read it.
And your math is still wrong. The cumulative probability associated with 2.5 standard deviations is 0.9938 as you can verify by looking at the entry for "2.5" in this table:
en.wikipedia.org
And 1- 0.9938 = 0.0072 which is the probability of exceeding 2.5 standard deviations to the downside so the number of years is 1/0.0072 = 138.8.
So you're wrong by almost a factor of 4. To get a 1 in 500 probability, you have to go to 2.88 standard deviations. Go look at the table for the entry for 2.88, find that it's 0.9980 and then compute 500 = 1/(1-0.9980). There, was that so hard?
---------------------------------------------------------------------------------------
Now explain to us all again how you are competent to report to us on your analysis of the statistical support for global theory. The fact is that you can't do simple standard deviation problems. You never took the class, you failed it, or you forgot it. Which is it?
Face the truth, you're deeply ignorant on the subject you're talking about. Like most people, you have no idea who to believe so you believe the talking heads you see on the media. At best, all you understand are the basic headlines. You're no scientist and you're not in a position to pass judgement on the work of scientists. You're certainly in no position to report to us your learned opinions because there's no learning behind them. Like most people, you just pass on information you've heard without the slightest idea if it's accurate or not.
Go bring your master and I'll debate him. You're not a challenge.
-- Carl
As long as we're on this subject, standard deviations only apply when the variable is a collection of independent normal random variables. Sea ice, as measured from year to year is neither normal nor independent. Estimating the a posteriori probabilities using multiples of standard deviation is abuse of statistics. See the wikipedia article on the subject, particularly this paragraph: en.wikipedia.org
I'll write more about this interesting subject in a separate post to follow by comparing with the financial markets. |
