I have created the Tables below, and the question I have is:

1. Find the name of the managers and the average salary of the employees they manage.

Table 1: Employee

Employee_name Street City

William Gates III University St Redmond Warren Buffett Alaskan Way Omaha Lakshmi Mittal 1st Ave London Carlos Slim Helu 1st Ave London Prince Gatlin 2nd Ave Birmingham Ingvar Kamprad University Ave Oslo Paul Allen First St Seattle Karl Albrecht Westlake Ave London Lawrence Ellison 20717 International Blvd. Silicon Valley Mark Zuckerberg First Avenue Silicon Valley Sheryl Sandberg Second Avenue Silicon Valley Dave Wehner Third Avenue Silicon Valley Mike Schroepfer Fourth Avenue Silicon Valley Chris Cox Sixth Avenue Silicon Valley Kenneth Thomson 20717 International Blvd. Silicon Valley Liliane Bettencourt 21 Rue de Miroir Lyon Bernard Arnault 18 Avenue de Suffren Paris Michael Dell 4533 South Austin Sheldon Adelson 4533 South Austin Theo Albrecht Westlake Ave London

Table 2: Works Employee_name Company_name Salary William Gates III Microsoft 1400000 Warren Buffett Exxon Mobil 230000 Lakshmi Mittal General Electric 60000 Carlos Slim Helu General Electric 400000 Prince Gatlin General Electric 50000 Ingvar Kamprad BP 80000 Paul Allen Microsoft 300000 Karl Albrecht BP 100000 Lawrence Ellison Oracle 98000 Mark Zuckerberg Facebook 650000 Sheryl Sandberg Facebook 450000 Dave Wehner Facebook 120000 Mike Schroepfer Facebook 94000 Chris Cox Facebook 300000 Kenneth Thomson Oracle 120000 Liliane Bettencourt Chanel 500000 Bernard Arnault Chanel 130000 Michael Dell Dell 900000 Sheldon Adelson Dell 80000 Theo Albrecht BP 56000

Table 3: Company Company_name City Microsoft Redmond Exxon Mobil Omaha General Electric London BP London Oracle Silicon Valley Facebook Silicon Valley Chanel Paris Dell Austin

Table 4: Manages Employee_name Manager_name Paul Allen William Gates III Carlos Slim Helu Lakshmi Mittal Karl Albrecht Ingvar Kamprad Theo Albrecht Ingvar Kamprad Kenneth Thomson Lawrence Ellison Sheryl Sandberg Mark Zuckerberg Dave Wehner Mark Zuckerberg Mike Schroepfer Sheryl Sandberg Chris Cox Sheryl Sandberg Bernard Arnault Liliane Bettencourt Sheldon Adelson Michael Dell