The normal distribution is characterized by the bell shaped curve.
My question is that which curve is bell shaped in the normal distribution? Is it the frequency histogram, the relative frequency curve, or the PDF that is bell shaped?
The normal distribution is characterized by the bell shaped curve.
My question is that which curve is bell shaped in the normal distribution? Is it the frequency histogram, the relative frequency curve, or the PDF that is bell shaped?
The normal distribution is continuous - it can take any value in the real numbers. Any value it takes has a zero probability of being exactly repeated - frequencies will be 0 or 1. So it has a probability density function, not a freqency curve.
A frequency histogram represents discrete values which may occur more than once. That might be for a discrete distribution (e.g. the Binomial) which is approximately normal, or for sample data from a normal distribution that has been grouped into ranges giving frequencies greater than 1. So when you see a freqency histogram in the classic bell shape, you're seeing something that approximates to, or derives from, a normal distribution.