Statistiques 1 Moyenne arithmétique 2 Variance

xini
x1x2...... xp
n1n2..... np
N
N=
p
X
i=1
ni=n1+n2+n3+... +np
x
x=Pnixi
N=n1x1+n2x2+... +npxp n1+n2+n3+... +np
f1f2fpx=f1x1+f2x2+... +fpxp
xi=
p
X
i=1
(fi.xi)
V
V=n1(x1−x)2+n2(x2−x)2+..... +np(xp−x)2
N=1 N(n1x2
1+n2x2 2+... +npx2 p)−x2
V
σ
σ=sn1(x1−x)2+n2(x2−x)2+..... +np(xp−x)2
n1+n2+... +np
L´ecart type est σ =√V

m
x1x2....
| {z }
50%
m ... xp−1xp
| {z }
50%
Q1Q2Q3
x1x2....
| {z }
Q1=25%
.. .. ....
| {z }
Q2=25%
.. .. ....
| {z }
Q3=25%
.. xp−1xp
| {z }
25%
Q3Q1