A humor piece in a reputable medical journal notes that people can't tell for sure whether parachutes are safe and effective because there has never been a properly randomized, double-blind, placebo-controlled study of parachute effectiveness in skydiving. Suppose a researcher were designing such a study.


Complete parts 1 and 2 below.


1)What is the factor in this experiment?

AJumping with or without a parachute

BThe parachutes

CHow the parachutes are distributed to the skydivers

DThe skydivers

2) What experimental units should be used?

ADifferent brands of parachutes B. Airplanes

CVolunteer skydivers

DThe research team