Comparing and sampling populations

2 videos
3 skills
When we are trying to make a judgement about a population, it is often impractical (or impossible) to observe every member of the population. Imagine trying to survey all 300+ million Americans to understand the likely outcome of the next presidential election! Because of this, much of statistics is collecting data from a representative and random sample. From the data collected from this random sample we can infer things about the greater population.

Reasonable samples

VIDEO 4:17 minutes
To make a valid conclusion, you'll need a representaive, not skewed, sample.

Valid claims

PRACTICE PROBLEMS
Practice figuring out whether we took a random sample and whether we're able to draw valid conclusions from our data.

Making inferences from random samples

PRACTICE PROBLEMS
Given a random sample, practice figuring out what can we reasonably infer about the entire population?

Comparing distributions with dot plots (example problem)

VIDEO 4:00 minutes
Sal examines two distributions in dot plots to draw conclusions about the times of Olympic swimmers.

Comparing distributions

PRACTICE PROBLEMS
Practice comparing distributions that are presented in dot plots, histograms, and box plots.