Question

unit 4 test: graphs and describing distributions multiple choice

1. were the extinctions that occurred in the last ice age more frequent among species of animals with large body sizes? a researcher gathers data on the average body mass (in kilograms) of all species known to have existed at that time. these measurements are values of

(a) a categorical variable.
(b) a quantitative variable.
(c) an invalid variable.
(d) a margin of error.
○ a
○ b
○ c
○ d

Explanation:

A categorical variable places individuals into groups or categories. A quantitative variable takes numerical values for which arithmetic operations like adding and averaging make sense. Body mass is measured in kilograms (a numerical value), and arithmetic operations on it (e.g., finding the average body mass of a set of species) are meaningful. So, it is a quantitative variable. A margin of error is related to sampling and confidence intervals (not relevant here). And it is a valid variable as body - mass can be measured.

Answer:

B. A quantitative variable.