Incorrect. Accident victims are not flown to the hospital in a helicopter unless their condition is very serious. So accident victims who are flown to the hospital in a helicopter are more likely to die due to their condition than accident victims who are driven to the hospital in an ambulance. The other two examples do not have an obvious lurking variable.
Correct. Accident victims are not flown to the hospital in a helicopter unless their condition is very serious. So accident victims who are flown to the hospital in a helicopter are more likely to die due to their condition than accident victims who are driven to the hospital in an ambulance. The other two examples do not have an obvious lurking variable.
Incorrect. Try again.
2