What the exam asks
Question 4 is structured into labeled parts (A, B, C, and sometimes D), often with subparts (i, ii). Each question is scored analytically out of 10 points, where each point is tied to a specific statistical component. Because the parts tell a connected story, a typical Question 4 might ask you to:
- Part A: Interpret a graph, regression output, or study design (Practices 2 and 3).
- Part B: Calculate a probability or expected value using a distribution or two-way table (Practice 3).
- Part C: Carry a value from Part A or B forward to evaluate a claim using either a descriptive comparison or a targeted part of an inference procedure (Practice 4).
Core ideas
Decoding the prompt by content area and practice
Before typing into Bluebook, read the entire scenario and map out what each part requires:
| Prompt language | Content area & practice | Required elements in your typed response |
|---|---|---|
| “Explain why this sampling/assignment method...” | Unit 1: Data Collection (Practice 2) | Identify the method, explain how it works in context, or state the scope of inference (generalization vs. causation) or direction of bias. |
| “Calculate the probability that...” or “Find the mean of...” | Unit 2: Probability (Practice 3) | Name the distribution and its parameters (e.g., ), state the boundary and direction (), or show the formula structure with substituted values. |
| “Based on the sample data / residual / summary statistics, is there support...” | Units 1 & 5: Descriptive (Practice 4) | Compare specific statistics, -scores, or predicted values () in context. Do not run a hypothesis test. |
| “Do the data provide convincing statistical evidence...” or “Based on the confidence interval...” | Units 3 & 4: Inference (Practice 4) | Use the -value compared to , or check whether the hypothesized value falls inside the interval, and conclude in context about the population parameter. |
Showing work for calculations in Bluebook
A naked numerical answer or a calculator command (binomcdf(10, 0.4, 3)) will not earn full credit. You must communicate the structure of the calculation using standard keyboard notation:
- Formulas: Show the substituted values and the final result:
z = (14.2 - 12.0) / 0.8 = 2.75. - Distributions: Write the distribution name, parameters, and inequality:
Normal with mean = 50 and SD = 4; P(X > 56) = 0.0668.