In the Maple & Birch `orders` sheet, the column `order_id` (1001, 1002, …, 1012) is which type of variable?

Answer

Categorical — an identifier; arithmetic on it is meaningless

Options - A. Categorical — an identifier; arithmetic on it is meaningless - B. Discrete numeric — the values are whole numbers that increase by one - C. Continuous numeric — it can be averaged, so it is a measurement - D. Ordinal — the later orders have the larger numbers Why - A. Correct — it labels each order. That it is made of digits changes nothing: 1006.5 is not an order. - B. The trap. Whole numbers that count something are discrete; these count nothing. They are names that happen to be digits. - C. A tool will average it, but the result means nothing. Being averageable by software is not the test. - D. Ordinal is a level of measurement (Lesson 2.3), and the sequence of IDs is bookkeeping order, not a ranking of the orders.