Suppose a new standardized test is given to 97 randomly selected third-grade students in New Jersey. The
Question:
Suppose a new standardized test is given to 97 randomly selected third-grade students in New Jersey. The sample average score Upper Y overbar Y
on the test is 56 points and the sample standard deviation, s Subscript Upper Y sY , is 10 points. The authors plan to administer the test to all third-grade students in New Jersey.
1. The 95% confidence interval for the mean score of all New Jersey third graders is (round to two decimal places).
2. Suppose the same test is given to 190 randomly selected third graders from Iowa, producing a sample average of 66 points and sample standard deviation of 13 points.The 90% confidence interval for the difference in mean scores between Iowa and New Jersey is (round to two decimal places).
Probability & Statistics for Engineers & Scientists
ISBN: 978-0130415295
7th Edition
Authors: Ronald E. Walpole, Raymond H. Myers, Sharon L. Myers, Keying