In a study, degree of help is defined as the amount of time between the emergency and the response of the bystander. The bystander who responds more quickly is considered to have been more helpful....

In a study, degree of help is defined as the amount of time between the emergency and the response of the bystander.  The bystander who responds more quickly is considered to have been more helpful.  The appropriate statistical test for the hypothesis that 'male bystanders are more helpful than female bystanders' is:

1. Chi square


2. t for 2 independent samples


3. Pearson's r


4. t-test for a single sample