For the following pick all that apply.

Leaving the airport in his rental car, Dexter wanted to increase the volume of the radio and reached for the knob that he thought was the volume control. He quickly established that it was not the control, because rotating it did not produce any change in the volume.

Question $24$Answer

a$.$

Method of difference

b$.$

Method of residues

c$.$

Cause: radio volume

d$.$

Method of concomitant variations

e$.$

Joint method of difference and agreement