Which statement describing this experiment is true? An experiment is proposed to measure the
effectiveness of a brand of sunscreen. Adult volunteers
are randomly assigned to one of two brands of
sunscreen and asked to enjoy a normal day at the
beach. Each volunteer is asked to report back to the
administrators after two hours, at which time both arms
are assessed for sun exposure.
O The volunteers are the explanatory variables.
O. The brands of sunscreen are the response
variables.
O The amount of time in the sun is the response
variable.
O The brands of sunscreen are the explanatory
variables.