How to include a join in a inner select

Question

I would like to include in my query the field (department_name) from the table (department), how can i use an inner join to get this result in the following query,...
select id,last_name||' '||first_name name, salary, dep_id,demora,
round(abs(count(case when demora>15 then 1 end) over ()
/ count(*) over ()*100-100),2)||'%' avg_delay
from(
select employee_id id, last_name,first_name, salary,department_id dep_id,
case when salary >10000 then 22
when salary <10000 and salary >5000 then 10
else 4
end demora
from employees)

Answer 1

I think this is enough
select employee_id id,last_name||' '||first_name name, salary, d.department_id dept_id ,department_name,
      case when salary >10000 then 22
           when salary <10000 and salary >5000 then 10
      else 4
      end demora,
      round(abs(count(case when salary>10000 then 1 end) over () / count(*) over ()*100-100),2)||'%' avg_delay
from employees e,departments d
where e.department_id = d.department_id(+);