"As a sixth grade teacher, you are concerned about the pre-algebra test that your class has to take at the end of the year in preparation for seventh grade. Their performance determines placement in pre-algebra or general math. The district scores for students placed in pre-algebra over the past several years reveal a mean score of 92 and a standard deviation of 4. After several weeks of preparation, you administer a practice test to your sixth graders. The result is a mean score of 94. Is the mean difference significant enough to lead you to believe that your class is ready to pass the pre-algebra test in May?"