All possible outcomes together must have probability 1. A statistic is a number that can be computed from the sample data. A parameter is a number that describes the population. In statistical practice, the value of a parameter is not known. Sample mean is a statistic.
Population mean is a parameter.
The letter in the solution section beside the answer to the first problem is the first letter in the answer to the riddle, the letter beside the answer to the second problem is the second letter, and so on. The word in the solution section beside the answer to the first problem is the first word in the answer to the riddle, the word beside the answer to the second problem is the second word, and so on. Use the t table to compute the confidence intervals and round answers to one decimal place.