Reading Books - 1 Population Mean Condence Intervals B 1. A Gallup poll conducted a random sample survey in 2005 asked 1006 Americans how many books did they read in the past year. Results of the survey indicated the mean to be 13.4 books, with a sample standard deviation of 16.6 books. Construct a 99% condence interval and interpret 1t_'_s_ meaning. 2. What is the population being considered here? 3. Is this using a Z or t distribution? How can you tell?