The following questions should be answered using SQL commands.

What is the average salary in Marketing department?

Rows 393 CSV JSON CSV JSON id first_name last_name address state zip_code phone email hire_date department_id job_title 1 Ma 78112 Morris Ave CT 6473 203-721-3388 mlayous 1997-07-02 2 Marketing Resea... Layous Hoopengardner 2 Ettie 39 Franklin Ave WA 99352 509-755-5393 ehoopengardner 1997-07-08 4 Automotive Sale... 3 Audry Yaw 70295 Pioneer Ct FL 33511 813-797-4816 ayaw 1997-07-10 5 Treasurer 4 Tasia Andreason 4 Cowesett Ave NJ 7032 201-920-9002 tandreason 1997-07-19 6 Customer Care ... 5 Vilma Berlanga 79 S Howell Ave MI 49546 1997-08-02 4 Wealth Manage... vberlanga pwide 6 Paris Wide 187 Market St GA 30342 4 Account Executi... 616-737-3085 404-505-4445 503-527-5274 907-385-4412 7 Nieves 4940 Pulaski Par... OR 3 CIO Gotter Paprocki 1997-09-12 1997-10-04 1997-10-10 97202 99501 ngotter Ipaprocki 8 Lenna 639 Main St AK 7 9 Meaghan Garufi 69734 E Carrillo... TN 37110 931-313-9635 1997-10-20 4 mgarufi cboulter Training Coordin... Sales Director Customer Care R... Customer Relati... 10 Carlee Boulter 8284 Hart St KS 67410 785-347-1805 1997-11-09 6 11 Avery Steier 93 Redmond Rd... FL 32803 407-808-9439 asteier 1997-12-25 6 12 Joanna Leinenbach 1 Washington St FL 33461 561-470-4574 jleinenbach 1998-01-17 1 Office Support S... Rows 393 CSV JSON CSV JSON id first_name last_name address state zip_code phone email hire_date department_id job_title 1 Ma 78112 Morris Ave CT 6473 203-721-3388 mlayous 1997-07-02 2 Marketing Resea... Layous Hoopengardner 2 Ettie 39 Franklin Ave WA 99352 509-755-5393 ehoopengardner 1997-07-08 4 Automotive Sale... 3 Audry Yaw 70295 Pioneer Ct FL 33511 813-797-4816 ayaw 1997-07-10 5 Treasurer 4 Tasia Andreason 4 Cowesett Ave NJ 7032 201-920-9002 tandreason 1997-07-19 6 Customer Care ... 5 Vilma Berlanga 79 S Howell Ave MI 49546 1997-08-02 4 Wealth Manage... vberlanga pwide 6 Paris Wide 187 Market St GA 30342 4 Account Executi... 616-737-3085 404-505-4445 503-527-5274 907-385-4412 7 Nieves 4940 Pulaski Par... OR 3 CIO Gotter Paprocki 1997-09-12 1997-10-04 1997-10-10 97202 99501 ngotter Ipaprocki 8 Lenna 639 Main St AK 7 9 Meaghan Garufi 69734 E Carrillo... TN 37110 931-313-9635 1997-10-20 4 mgarufi cboulter Training Coordin... Sales Director Customer Care R... Customer Relati... 10 Carlee Boulter 8284 Hart St KS 67410 785-347-1805 1997-11-09 6 11 Avery Steier 93 Redmond Rd... FL 32803 407-808-9439 asteier 1997-12-25 6 12 Joanna Leinenbach 1 Washington St FL 33461 561-470-4574 jleinenbach 1998-01-17 1 Office Support S