Define suitable populations from which the following samples are selected:

(a) Persons in 200 homes are called by telephone in the city of Richmond and asked to name the candidate that they favor for election to the school board.

(b) A coin is tossed 100 times and 34 tails are recorded.

(c) Two hundred pairs of a new type of tennis shoe were tested on the professional tour and, on the average, lasted 4 months.

(d) On five different occasions it took a lawyer 21, 26, 24, 22, and 21 minutes to drive from her suburban home to her midtown office.