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## Sampling and observational studies

Current time:0:00Total duration:2:12

# Identifying a sample and population

AP Stats: DAT‑2 (EU), DAT‑2.A (LO), DAT‑2.A.1 (EK), DAT‑2.A.2 (EK)

## Video transcript

- [Narrator] Administrators
at Riverview High School surveyed a random sample
of 100 of their seniors to see how they felt
about the lunch offerings at the school's cafeteria. So you have all of the seniors, I'm assuming there's more
than a hundred of them, and then they sampled a hundred of them. So this is the sample. So the population is all of
the seniors at the school. That's the population, all of the seniors. And they sampled a hundred of them. So the hundred seniors that the talked to, that is the sample. That is the sample. So they tell us, identify the population and the sample this setting. So let's just see which if these choices actually match up to what I just said. And like always, I encourage
you to pause the video and see if you can work
through it on your own. So, the population is all high
school seniors in the world; the sample is all of the
seniors at Riverview High. No, this is not right. We're not trying to get an indication of how all of the high school
seniors in the world feel about the food at
Riverview High School. We're trying to get an indication of how the seniors at Riverview High School feel about the lunch at
the school's cafeteria. So they did a sample of hundred of them. So this is definitely not going to be-- let me cross this one out. The population is all
students at Riverview High; the sample is all of the
seniors at Riverview High. Well, they clearly didn't
sample all of the seniors, they sampled a hundred of the seniors. So this isn't gonna be right either. Let's hope that the third
choice is working out. The population is all
seniors at Riverview High; the sample is the
hundred seniors surveyed. Yep, that's exactly what we talked here. We're trying to get an
indication about how all of the seniors at Riverview High feel about the food, the lunch offerings. We probably think it's impractical or the administrators
feel it's impractical to talk to everyone. So, to get exactly what
the population thinks. So instead they're gonna do a random sample of a hundred of them. So the sample is the hundred seniors who are actually surveyed.