A researcher asks random samples of residents of two separate counties as to whether they had purchased organically grown food in the last three months. He wants to determine whether the proportion of residents of one county who purchase organically grown food is greater than the proportion of residents of the second county who purchase organically grown food. Choose the appropriate test and name the population(s).
A)One-proportion z-test; the population is all residents of a state.
B)One-proportion z-test; the population is all residents of the first county.
C)Two-proportion z-test; one population is all residents of the first county and the other population is residents of the second county.
D)Two-proportion z-test; one population is all adults who buy organically grown food and the other population is all adults who do not buy organically grown food.

Question

Quizplus · Accepted Answer

The researcher is comparing the proportions of two separate groups (residents of two different counties) regarding a specific behavior (purchasing organically grown food), which necessitates a two-proportion z-test. Each county's residents constitute a separate population for the purpose of this analysis.

A Researcher Asks Random Samples of Residents of Two Separate