PROVECT Figure 3. 3344555 M19420228 Spoe Given the above database, and the primary/foreign keys used for it as discussed in the course slides, specify how you would write the following queries using relational algebra notation? 6 Retrieve the employee first name, last name, department number, and supervisor last name for all employees who have a salary that is at least S30,000 but is less than $50,000 7. Retrieve the average salary over all employees in the company . Retrieve the average salary for each department in the company (report by department number) 9. Retrieve the first names and last names of all employees who have a salary greater than the average salary for the whole company. 10. Retrieve the first names and last names of all employees who have a salary greater than the average salary for the department they work for. 1. Retrieve the first name, last name, salary, and department number for all employees. 2. For the department named "Administration", retrieve the first name, last name, and salary of each employee working for the department s. Retrieve the employee last name, dependent first name, and relationship of dependents of employees who work in the department named Research 4. Retrieve a list of the names of employees in the Research' department and the names of the projects they are assigned to. s. Retrieve the employee first name, last name, department number, and supervisor last name for all employees. Your query should include all employees, including those with no supervisor