Update The Salary Of Each Manager To Be Double The Average Salary Of The Employees He/she Manages

create table employee(empid int,empname varchar(20),managerid int not
null, sal int)

insert into employee values(1,'ranga',22,5000)
insert into employee values(2,'satish',22,8000)
insert into employee values(3,'sunil',11,4500)
insert into employee values(4,'sridhar',22,2000)
insert into employee values(5,'ramesh',33,12000)
insert into employee values(6,'srini',22,16000)
insert into employee values(7,'sashi',33,54000)
insert into employee values(8,'rajani',22,71000)
insert into employee values(9,'praveen',11,6060)
insert into employee values(10,'bhaskar',22,11120)
insert into employee values(11,'baba',33,9000)

create table employment (managerid int,managername varchar(20),sal int)

insert into employment values(11,'rob',2500)
insert into employment values(22,'babu',5000)
insert into employment values(33,'ram',6000)



now my problem is

Update the salary of each manager to be double the average
salary of the employees he/she manages

pls help

sati