The central limit theorem: the arithmetic mean of a sufficient number of independent random variables with means and variances will be a normal random variable. It's just that lots of natural phenomena are like this, or appear to be sufficiently like this. Please see the wikipedia article for more details.
The standard normal curve is symmetrical.
It is a normal curve with mean = 0 and variance = 1.
the standard normal curve 2
Answer this question...similarities and differences between normal curve and skewness
A bell shaped probability distribution curve is NOT necessarily a normal distribution.
The standard normal curve is symmetrical.
No, the normal curve is not the meaning of the Normal distribution: it is one way of representing it.
It is a normal curve with mean = 0 and variance = 1.
the standard normal curve 2
The area under the standard normal curve is 1.
There is no such thing as an "ormal curve". And a Normal curve IS symmetrical!
Answer this question...similarities and differences between normal curve and skewness
The area under the normal curve is ALWAYS 1.
Your question makes no sense. Significant is a word related to tests. The normal curve is a distribution, not a test.
The Gaussian curve is the Normal distributoin curve, the commonest (and most studied) of statistical distributions.
A bell shaped probability distribution curve is NOT necessarily a normal distribution.
yup, it's a bell curve