Community College Tuition. Use the following information for Exercises 53–63. The College Board reported that the mean tuition and fees at community colleges nationwide for the 2013–2014 academic year was $3264. Data were gathered on the total tuition and fees for a random sample of 10 community colleges in 2015. The normal probability plot is shown here.
Question 9.259
63. Challenge Exercise. Note that we have concluded that there is insufficient evidence that the population mean cost has changed, but evidence exists that the population mean cost has increased. How can the mean cost have increased without changing? Explain what is going on here, in terms of either critical regions or -values.
9.4.63
Since the for the two-tailed test is twice the for the one-tailed test, it is possible to conclude that there is insufficient evidence that the population mean cost has changed, but there is evidence that the population mean cost has increased if is between the two .