Samples of water are taken from the local river in town A over a one-week period, at random times and locations, both downstream and upstream, to establish the effect of activities in the town on the acidity of the river. The population in this scenario is:[Fill in the blank]单项选择题
A
The people living in town A
B
The local river in town A
C
All water collected from the river in town A
D
All activities in town A

Question

Samples of water are taken from the local river in town A over a one-week period, at random times and locations, both downstream and upstream, to establish the effect of activities in the town on the acidity of the river. The population in this scenario is:[Fill in the blank]单项选择题

A

The people living in town A

B

The local river in town A

C

All water collected from the river in town A

D

All activities in town A

BlackTom AI · Accepted Answer

The question asks to identify the population in a study design where water samples are drawn from the local river over one week at random times and places to assess the effect of town activities on river acidity.
Option 1: The people living in town. This is not the population because the study is about the river water, not about the residents themselves.
Option 2: The local river in town A. This describes the environment being studied, but a population is the entire set of items or elements being considered for measurement, not the setting alone. The river as a whole could be seen as the scope, but we need to be precise about what constitutes the population in this sampling context.
Option 3: All water collected from the river in town A. This choice captures all possible water samples that could be taken from the river at any location and time within town A. It represents the complete set of units the study aims to describe or generalize about, given the sampling plan.
Option 4: All activities in town A. This refers to actions or processes, not to the measurements of the river water’s acidity, and thus does not match the data being studied.

In designing sampling or population concepts, we align the population with the total collection of units from which we would like to draw inferences. Here, the research targets the acidity of river water across places and times within town A, so the natural population comprises all water from that river in town A that could be sampled. The wording in option 3 best aligns with that idea, as it encompasses all potential water samples from the river in the study area. The other options miss the scope of what is being measured or confuse the subject (people, river as a whole, or town activities) with the actual sampling units.