Q1 L1 · Quiz
Weekly quiz · Learning to Test Ideas: Controlled Experiments
Assessment Appendix — AP Statistics · Week 1 Quiz
Quarter 1, Week 1 · Lessons 1.1–1.2 · Learning to Test Ideas: Controlled Experiments; Variables in the Garden: Individuals, Variables, Parameters, and Statistics
| # | Item | Answer / look-fors / scoring | Pts | Lesson · standards |
|---|---|---|---|---|
| 1 | Which term best matches this description? A procedure in which a researcher deliberately changes one variable to see its effect on another; without manipulation it is an observation. | (A) experiment. | 1 | L1.1 · CED Topic 1.1, 1.13; LO 1.1.A, 1.1.B, 1.13.A; Skill 1.A, 2.A |
| 2 | Which term best matches this description? A comparable neighborhood that did not get trees, measured over the same summer with the same instruments; it shows what would have happened anyway. | (E) control group. | 1 | L1.1 · CED Topic 1.1, 1.13; LO 1.1.A, 1.1.B, 1.13.A; Skill 1.A, 2.A |
| 3 | Choose the word or phrase that best completes the sentence: An experiment changes one thing on purpose and compares the result to a ________ that is identical in every other way. Without the control, we cannot claim cause and effect. | (E) control group. | 1 | L1.1 · CED Topic 1.1, 1.13; LO 1.1.A, 1.1.B, 1.13.A; Skill 1.A, 2.A |
| 4 | Pepper heights (cm) have Q1 = 6.0, Q3 = 8.0, and a maximum of 11.5. Using the 1.5 × IQR rule, which statement is correct? | (D) The upper fence is 11.0, so 11.5 is an outlier. IQR = 2.0; upper fence = 8.0 + 1.5(2.0) = 11.0 < 11.5. | 1 | L1.1 · CED Topic 1.1, 1.13; LO 1.1.A, 1.1.B, 1.13.A; Skill 1.A, 2.A; item skill 2.A |
| 5 | The class measures every 5th plant along the path after a random start. Which sampling method is this? | (C) systematic random sample. Match the selection process to the method definitions. | 1 | L1.1 · CED Topic 1.1, 1.13; LO 1.1.A, 1.1.B, 1.13.A; Skill 1.A, 2.A; item skill 1.C |
| 6 | Short Free Response: Answer each part using evidence from this week’s garden investigations. | 4 | L1.1, 1.2 · CED Topic 1.1, 1.13; LO 1.1.A, 1.1.B, 1.13.A; Skill 1.A, 2.A; CED Topic 1.2; LO 1.2.A, 1.2.B, 1.2.C; Skill 2.A | |
| (a) What is the difference between an experiment and an observation? | An experiment deliberately changes a variable; an observation records what happens without manipulation. | 1 | ||
| (b) Why is a control group essential? | It provides a baseline that shows what would happen without the treatment, so a difference can be attributed to the treatment. | 1 | ||
| (c) A sports drink company surveyed 50 athletes who drink its product and 80% said they felt stronger. Identify two problems with this study and describe a better design. | Problems: no control group, self-report bias, no random assignment, athletes already chose the drink. Better: randomly assign athletes to the drink or a look-alike placebo, measure a performance variable (sprint time), keep training constant, and use a large sample. | 1 | ||
| (d) Identify the observational units in a study of 30 tomato plants. | The tomato plants. | 1 |