Thirteen exercises from the book

Every problem here is an end-of-section exercise from Saylor's Introductory Statistics, chapter 7, reproduced word for word and labelled with its section and number — the ones we did not do in class. Type each answer, check it, take a hint if stuck, then read the full solution. Take z_α/2 and t_α/2 to three decimals from the book's t table (Figure 12.3) ↗ — its last row, ∞ [z], gives every z you need — keep σ/√n unrounded, and round the margin the way the book's answer does. Parts that ask you to verify, comment or interpret are answered in the solution.