Lucas is a sommelier, or a wine taster, whose task is to taste the slightest flavor differences between two wines. This is an example of .

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.