Problem: Safety engineers must determine whether industrial workers can operate a machine's emergency shutoff device. Among a group of test subjects, 66% were successful with their left hands, 85% with their right hands, and 51% with both hands.
a) What percent of these workers could not operate the switch with either hand?
b) Are success with right and left hands independent events? Explain.
c) Are success with right and left hands mutually exclusive? Explain.