P^2+Σ2P

8/10 is 8 heads in each 10 times. This is qite rare . 80% of the heads are in 99.9%. The red is the area. t≧0 In this case, t is 0.8, and -t is 0.2. They are symmetry. 1/100 is the possibilty to have 80% of the head. This is very difficlt like finding rich men . Var(Z)＜∞ ∴ You may know Bernoulli trial. n=10, and k=8. P(X=8)=0.044≒4/100. Therefore, you may have 1～4 of (8/10) heads in each 100 times .You can't predict anything because of Zero.

Whenever you toss your coins, you are close to normal distribution. You can see Gaussian function . μ is the average, and σ^2 is the distribution. Y is E(X) . I tossed coins 100 times. NORMDIST(x,0.5,(x-0.5)^2,0) You may have 80% of the head once (1.7%). When you are around Y which is the average, it is almost Zero. You need to go far beyond that. It is quite rare.0.5 is null, and 0.8 and 0.2 are symmetry. NORMDIST(0.8,0.5,(0.8-0.5)^2,1)≒0.999 X=0.6 is 100% The average is normal and Zero, but 9/10 and 10/10 is the difficulty. It is narrower and close to Zero. You may talk about singularity.

It is hard to see rich men. This is called Markov’s Inequality. E[X] is the average , although I don't reach it. X is a discrete random variable. ∴ a＞0

This is an even function which is symmetry by the Y-axis. ∴ This is the inflection point. You still see the square . f(0)=1 The average is the top which is called normal distribution. μ is the average, and σ^2＞0. R=(-∞,∞)