Review statistics for two categorical variables for AP Statistics and try 2 free AP-style practice questions. 12 questions on this topic in AP Statistics · Unit 2 · Exploring Two-Variable Data.
A hospital reviewed billing records for 800 patients treated last year, classifying each patient by department (emergency, surgery, or outpatient) and by insurance status (insured or uninsured). The results are summarized in the table below.
| Insured | Uninsured | Total | |
|---|---|---|---|
| Emergency | 205 | 95 | 300 |
| Surgery | 168 | 32 | 200 |
| Outpatient | 270 | 30 | 300 |
| Total | 643 | 157 | 800 |
Based on the table, which of the following is closest to the marginal relative frequency of patients who are uninsured, out of all 800 patients?
A department store surveyed 500 shoppers about their satisfaction with their most recent visit, classifying each shopper by the store section visited (electronics, clothing, or grocery) and by satisfaction level (satisfied or unsatisfied). One entry in the table below, marked with a question mark, was not recorded due to a data entry error.
| Satisfied | Unsatisfied | Total | |
|---|---|---|---|
| Electronics | 112 | 38 | 150 |
| Clothing | ? | 45 | 175 |
| Grocery | 140 | 35 | 175 |
| Total | 382 | 118 | 500 |
Based on the table, what is the value of the missing entry, marked with a question mark, in the Clothing/Satisfied cell?
Full practice for AP Statistics · Unit 2 · Exploring Two-Variable Data: timed tests, step-by-step explanations for every answer, and AI grading for free-response questions.
Start practicing freeAnswer, then see why
The price of gasoline rises 10% and the quantity demanded falls 5%. What happens to total revenue?
Not quite. The answer is B.
Why the other options are wrong
AI grading for free-response
Write your FRQ answer and get it scored point by point against the AP rubric, with the line from your answer that earned or missed each point.
Reason: Correctly identifies demand for gasoline as inelastic.
Evidence: "The price of gasoline rises and the quantity falls only a little."
Reason: Graph shows relatively inelastic demand.
Evidence: Draws a steep demand curve.
Reason: Correct new equilibrium price.
Evidence: Shifts supply left, P1 → P2.
Reason: With inelastic demand, a price increase raises total revenue.
Evidence: "Revenue goes down."