Использование простой итерации.
Пример:
d={'POU': ['KO', '0.9.8', '0.99', '0.54'],
'TAN': ['LA', '9', '7.5', '0.0'],
'EST': ['RA', '2', '6.5', '10.01']}
x = [1,2, 3]
c = 0
for k,v in d.items():
v.append(x[c])
c+=1
print(d)
Вывод:
{'TAN': ['LA', '9', '7.5', '0.0', 1], 'POU': ['KO', '0.9.8', '0.99', '0.54', 2], 'EST': ['RA', '2', '6.5', '10.01', 3]}