The director of admissions at the University of Maryland, University College is concerned about the high cost of textbooks for the students each semester. A sample of 25 students enrolled in the university indicates that x(bar) = $315.40 and s = $43.20. Using a significance level of .1, what are the boundaries of the confidence interval? The director of admissions at the University of Maryland, University College is concerned about the high cost of textbooks for the students each semester. A sample of 25 students enrolled in the university indicates that x(bar) = $315.40 and s = $43.20. A mean that is not in a confidence interval is rejected by the confidence interval, and we say the evidence against the mean is significant. At the 0.10 level of significance, is there evidence against mean $300? 302.438 - 326.184 300.618 - 330.182 297.485 - 327.820 282.871 - 338.475