Identify the level of measurement (nominal, ordinal, interval, ratio) used in each of the following.

a. The weights of people in a sample of elevator passengers

b. A movie critic’s ratings of “must see; recommended; not recommended; don’t even think about going.”

c. A movie critic’s classification of “drama; comedy; adventure.”

d. Bob, who is different in many ways, measures time in days, with 0 corresponding to his birth date. The day before his birth is 1, the day after his birth is 1, and so on. Bob has converted the dates of major historical events to his numbering system. What is the level of measurement of these numbers?