Question: Reading scores in Atlanta The Trial Urban District Assessment (TUDA) is a government-sponsored study of student achievement in large urban school districts. TUDA gives a reading test scored from 0 to 500. A score of 243 is a "basic" reading level and a score of 281 is "proficient." Scores for a random sample of 1470 eighth-graders in Atlanta had x - = 240 with standard deviation 42.17.24
(a) Calculate and interpret a 99% confidence interval for the mean score of all Atlanta eighth-graders.
(b) Based on your interval from part (a), is there good evidence that the mean for all Atlanta eighth-graders is less than the basic level? Explain.