Partial Correlation

Hello everybody,

normally I wouldn't use a forum but this is a last resort.

3. SQ3: Is there a linear relationship between engine size and miles per gallon when controlling for vehicle type?
4. SQ4: Do vehicle characteristics (region of sale, engine cylinders, engine size, horsepower, wheelbase, curb weight, fuel capacity, and fuel efficiency) predict the difference between sale price and resale price?
5. SQ5: Do vehicle characteristics (as in #4) individually predict the difference in sale and resale price?

Subquestion 3: engine size and miles per gallon are continuous while vehicle type is nominal (1= truck; 2=automobile), I thought for partial correlation all 3 needed to be continuous so I consider it to be impossible however Im not sure. This assignment is on correlation, partial correlation and multiple regression.

Subquestion 4 and 5: Maybe its due to english not being my native language but do you guys see the difference between these two questions?

These exercises need to be done in SPSS.

Thank you and I hope I don't give you guys too much of a headache,