A random sample of 60 second-graders in a certain school district are given a standardized mathematics skills test. The sample mean score is =x53. Assume the standard deviation of test scores is =σ9....

A random sample of 60 second-graders in a certain school district are given a standardized mathematics skills test. The sample mean score is =x53. Assume the standard deviation of test scores is =σ9. The nationwide average score on this test is 55. The school superintendent wants to know whether the second-graders in her school district are different from the nationwide average. Use the =α0.10 level of significance and the critical value method.