Variable Discrete Continuous (a) The number of your fellow classmates who have used the World Wide Web for information on Seasonal Affective Disorder (b) The total amount of time that customers spend this week listening to telephone "hold" music while calling 1-800-PARCELS (c) The number of students, in a class of , who improve their score from the first midterm to the second midterm (d) The score (either , , , or with being the worst and being the best) given by a quality-control manager after an equipment inspection