14. List the address, square footage, owner number, service ID, number of estimated hours, and number of spent hours for each service request on which the category number is 4 . 15. Repeat Exercise 14, but this time be sure each property is included regardless of whether the property currently has any service requests for category 4. 16. Repeat Exercise 15 using a different SQL command to obtain the same result. What is the difference between the two commands