For each of the following examples, identify the independent and dependent variables and indicate whether the research involves the use of descriptive or inferential statistics. Justify your answer.

(a) A researcher wants to determine how the Gross Domestic Product (GDP) affects the number of unemployed people in Canada.

(b) Researchers are trying to understand whether students' opinions about the quality of food at the cafeteria varies with their ages based on results from a sample of 100 students.

(c) A researcher is trying to figure out if the incidence of breast cancer in Alberta is influenced by CO2 emissions from the oil sands.

(d) A researcher is conducting a study to determine if men and women rate the quality of a new automobile differently, gathered from 1,000 new buyers.

(e) University administrators want to know whether average GPAs differ across student majors (e.g., sociology, math, or history) based on total student records at the U of A.