Whats the independent and dependent variables

a drag racer wants to see if the speed of a race car can be altered depending on the type of fuel used-alcohol, nitrous, or gasoline.

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z