０００LLL - 経済統計練習帳

def bi(n,k,p1):
 
    c1=1
    for i in range(n):
       c1=c1*(i+1)
 
    c2=1
    for i in range(k):
        c2=c2*(i+1)
 
    c3=1
    for i in range(n-k):
        c3=c3*(i+1)
 
    b1=c1/(c2*c3)
 
    b2=(1-p1)**(n-k)
    b2=b2*p1**k
 
    return b1*b2
 
p=[0.25,0.5,0.75]
pre=[0.3,0.4,0.3]
 
z=[]
for i in range(3): 
    ans = pre[i]*bi(8,3,p[i])
    z.append(ans)
z1=0    
for i in range(3):
    z1=z1+z[i]
 
for i in range(3):
    z[i]=z[i]/z1
 
print(z)