6.2. (a) The sample mean is x̄ = 25, and the sample standard deviation is s = 5. (b) A 95% confidence interval for the mean is (23.04, 26.96).
: Because the author teaches at Carnegie Mellon University, some solutions to specific homework problems based on the book are available directly on the CMU Statistics website . Book Overview and Usage Tips
Most "full" manuals still skip the hardest problems (e.g., Chapter 15: "Locally most powerful tests"). Students assume those problems are unimportant. In reality, they are often the core of PhD qualifying exams.