In a series circuit containing 1 bulb, the voltage of the battery was increased from 1.5 V to 3.0 V. The brightness of the bulb increases?
G

Automobile fuel efficiency is often measured in miles that the car can be driven per gallon of fuel (mpg). heavier cars tend to have lower fuel efficiencies (lower mpg ratings). which variable (weight or fuel efficiency) is most naturally considered the explanatory (predictor) variable in this context?