4x time 10x (I think)
Here, this will help-
http://www.cas.miamioh.edu/mbiws/microscopes/Magnification.html#totalmagnification
A. Increase until it reaches it's maximum. Sound travels through air and as the amount of air in the jar increases, the loudness or amplitude of the bell increases until it reaches it's maximum at normal air pressure.
Answer:
I think is o or mavey it could be D
I would say it’s “B” for the reason that the student did not experiment with a short ramp and large ball as well as a large ramp and a short ball. They have to do those experiments as well before drawing their conclusion.