- A probability is a measure of the expectation that an event will occur.
- Probabilities lie between 0 and 1.
- We shall first explore this concept in terms that are familiar to you.
Forget the Formulation
The probability density function of normal distribution is:
Most students are suffering from understanding about this formulation. My suggestion is that you should forget about this formulation and focus on the shape and area of the normal distribution.
Shape of Normal Distribution
Normal distribution is symmetric “bell-shaped” distribution with unlimited range.
Effect μ and σ
Standard Normal Distribution
The normal distribution with µ=0 and σ=1 is called “standard normal distribution”.
Example (Source: STAT170):
IQ is normal distributed with µ=100 and σ=15.
What’s the Z-Scores of person with IQ=130?