from math import sqrt

def moyenne(x1,x2,x3,x4,x5):
  m = (x1+x2+x3+x4+x5)/5
  return(m)

def ecart(x1,x2,x3,x4,x5):
  m = moyenne(x1,x2,x3,x4,x5)
  v = ((x1-m)**2+(x2-m)**2+(x3-m)**2+(x4-m)**2+(x5-m)**2)/5
  e=sqrt(v)
  return(e)