Thread: Statistics notation

In my lecture notes on confidence intervals the lecturer wrote this:

Recall that measurements tend to follow a normal distribution. To describe the normal distribution and answer useful questions (as in the previous chapter), we need to know two numbers; the expectation or mean μ and the standard deviation (square root of the variance) σ. Then the quantity we measure X follows the normal distribution:
X ~ N(μ, σ²)

I don't understand the notation of that bolded text. I know X is a random variable, μ is the population mean and σ is the population standard deviation but what does the ~ mean? Also the N(μ, σ²) I assume means normal distribution but is that some kind of standard notation for distributions? For example if I said N(23,9) would that mean the normal distribution with a mean of 23 and standard deviation of 9?[/b]

To repeat what I said in another forum. Mean = 23, variance = 9, standard deviation = 3.

Originally Posted by mathman

To repeat what I said in another forum. Mean = 23, variance = 9, standard deviation = 3.

I know of one other forum where this guy has posted the same question, the answer to which is painfully obvious (Your response is, of course, correct.) You did not respond in that one. So we have a loweer bound of 3 for the number of forums with the same post/question.

Annoying isn't it ?

Originally Posted by DrRocket

Originally Posted by mathman

To repeat what I said in another forum. Mean = 23, variance = 9, standard deviation = 3.

I know of one other forum where this guy has posted the same question, the answer to which is painfully obvious (Your response is, of course, correct.) You did not respond in that one. So we have a loweer bound of 3 for the number of forums with the same post/question.

Annoying isn't it ?

What is the other forum that you saw this question?

Originally Posted by mathman

Originally Posted by DrRocket

Originally Posted by mathman

To repeat what I said in another forum. Mean = 23, variance = 9, standard deviation = 3.

I know of one other forum where this guy has posted the same question, the answer to which is painfully obvious (Your response is, of course, correct.) You did not respond in that one. So we have a loweer bound of 3 for the number of forums with the same post/question.

Annoying isn't it ?

What is the other forum that you saw this question?

http://www.scienceforums.net/topic/5...tics-notation/