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AP®︎/College Statistics

Course: AP®︎/College Statistics>Unit 6

Lesson 1: Introduction to planning a study

Identifying a sample and population

AP.STATS:
DAT‑2 (EU)
,
DAT‑2.A (LO)
,
DAT‑2.A.1 (EK)
,
DAT‑2.A.2 (EK)
CCSS.Math:
Identifying a sample and population.

Want to join the conversation?

• If I have a data set of one individual's running time over 10 wks,
Will it be a sample or a population data?
• This will be a sample, as you are observing the running time of only one individual
• I feel some of these problems on population/sample are ambiguously worded.

There's one about interest in out-of-state cars crossing a multi-lane toll bridge, and they sample every tenth car in one lane via a camera. The correct choice was population = all the cars in the one lane.

To me, this is incorrect. The setup clearly said interested in out-of-state cars crossing the toll bridge. We weren't told that out-of-state traffic only uses one lane, and it would be a weird leap to infer that as well.

We also weren't told there was any difference between the lanes. For all we know they only had one camera available for this and they picked a lane at random from which to sample. So it shouldn't matter from which lane or lanes they are drawing their sample, to me the sample is every tenth car in the photographed lane and the population they were after was all out-of-state traffic on the bridge. The population is the ENTIRE group we are interested in, and as phrased that means all the out-state-traffic on the whole bridge.

There is nothing in the question as it is phrased to tell me that only traffic in one lane is their interest. They sampled one portion of one lane of the bridge to extrapolate to all traffic on the bridge.

Where am I wrong on this?
• Is a research question different from a hypothesis?
Do we employ different strategies to gauge outcomes in both cases?
I read an article, and there was a definition of statistical analysis, and it goes like this;

Statistical analysis means investigating trends, patterns, and relationships using quantitative data. To draw valid conclusions, statistical analysis requires careful planning from the very start of the research process.
You need to specify your hypotheses and make decisions about your research design, sample size, and sampling procedure.

If you have noticed, in the second paragraph, it says that you need to specify your hypothesis first in order for the analysis to even take place. So does that mean we can't use statistical analysis with research questions?
But, it's indeed not the case as we, seldom, collect data for research questions as well, don't we? So, what's this conundrum?
• Which of these samples is most representative of the entire school population?
(1 vote)
• What does senior mean exactly in USA ? All of the students in a high school or just the final year of a high school
(1 vote)
• Tell me if I am correct. So Basically, The Population is the total? Then the Sample is the people getting surveyed?
(1 vote)
• how do people know how to work at their job
(1 vote)
• A population is the entire group that you want to draw conclusions about. A sample is the specific group that you will collect data from.
(1 vote)
• I need help with this question that may or may not relate to this video:

Jean polled a random sample from a population and calculated a sample statistic. Jean can use this statistic to draw an inference about what?

A. the corresponding sample parameter
B. the population size
C. the corresponding population statistic
D. the corresponding population parameter

It would be awesome if someone could explain this in detail to me!
(1 vote)
• this is all very confusing, i will not lie.