Could you find the names of all the departments, please?
select dept_name from department
What about classes with the course description "Statistics"?
select * from course where crs_description like '%statistics%'
What department name offers that course description?
select t2.dept_name from course as t1 join department as t2 on t1.dept_code = t2.dept_code where t1.crs_description like '%statistics%'
How many course credits are each of those worth?
select crs_credit from course where crs_code in ( select t1.crs_code from course as t1 join department as t2 on t1.dept_code = t2.dept_code where t2.dept_name = "Computer info. Systems" )