Identify the explanatory variable and response variable in each of the studies d
ID: 2956270 • Letter: I
Question
Identify the explanatory variable and response variable in each of the studiesdescribed here.
a.
A study of cell phone use and primary brain cancer suggested that cell
phone use was not associated with an elevated risk of brain cancer.
b.
Records of more than three-quarters of a million surgical procedures
conducted at 34 different hospitals were monitored for anesthetics
safety. The study found a mortality rate of 3.4% for one particular
anesthetic. No other major anesthetics were associated with mortality
greater than 1.9%.
c.
In a landmark study involving more than three-quarters of a million
individuals in the United States, Canada, and Finland, subjects were
randomly given either the Salk polio vaccine or a saline (placebo)
injection. The vaccinated group experienced a polio rate of 28 per
100,000 while the placebo group had a rate of 69 per 100,000. A
third group that refused to participate had a polio rate of 46 per
100,000.
Explanation / Answer
(a) Explanatory variable : The usage of cell phone Response variable : risk of brain cancer (b) Explanatory variable : Records of more than three-quarters of a million surgical procedures Response variable : Mortality rate for one particular anesthetic (c) Explanatory variable : The salk polio vaccine or a saline injection Response variable : Polio rate