Question 1
The annual salaries, in thousands of dollars, of the 10 employees at a small firm are 38, 41, 42, 44, 45, 47, 48, 52, 55 and 210. Which pair of summaries best describes the center and variability of these salaries?
AP Statistics Unit 1 review
Unit 1 is the largest unit: 20–30% of Section I. It covers describing one variable and how data are collected.
| Weight | 20–30% of the multiple-choice section |
|---|---|
| Topics | 1.1 to 1.13 |
Describing data
- Describe shape, center, variability and unusual features, in context.
- Median and IQR resist outliers; mean and standard deviation do not.
- Adding a constant shifts the center but not the spread; multiplying scales both.
Collecting data
- Random selection lets you generalize to the population.
- Random assignment lets you conclude cause and effect.
- A bigger sample does not fix a biased method.
Try 3 questions
Question 2
A university has 6,000 undergraduates in four class years. To survey students about campus housing, the dean randomly selects 50 students from each class year. What sampling method is this?
Question 3
A farmer tests two fertilizers on 20 plots. Ten plots are on a hillside and ten are in a valley, and soil differs between the two places. Which design is best?
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What is on AP Statistics Unit 1?
Exploring one-variable data (graphs, summaries, outliers, z-scores) and collecting data (sampling methods, bias, observational studies and experiments).