In a study on the monthly consumption expenditure of students in a university in Beijing, it was found that besides the monthly income level of their families, the students' consumption expenditure was also affected by factors such as whether they had received a scholarship at school, whether they came from rural areas or urban areas, whether they were from economically developed areas or underdeveloped areas, and gender. Try to set an appropriate model and derive the average level of student consumption expenditure under the following circumstances:

(1) Female students from underdeveloped rural areas who do not receive scholarships.

(2) Male students from less developed urban areas get scholarships.

(3) Rural girls from developed areas get scholarship.

(4) Male students from developed urban areas do not receive scholarship.