Thirteen exercises from the book

Every problem here is an end-of-section exercise from Saylor's Introductory Statistics, chapters 3 and 4, 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. Give probabilities to four decimals, as the book does. Parts that ask you to explain or interpret are answered in the solution.