Research regarding psychological treatment for borderline personality disorder suggests that appears to be helpful in improving mood and reducing suicidal and self-injurious behaviors.

For each of the following examples of data, determine which scale of measurement is used. a) the number of miles joggers run per week. b) the starting salaries of graduates of mba programs c) the months in which a firm's employees choose to take their vacations. d) the final letter grades received by students in a math course.