12. 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 the .10 level of significance, is there evidence that the population mean is above $300?

A mean that is not in a confidence interval is rejected by the confidence interval, and we say there is evidence.

1.No, because 300 is below the lower limit of the confidence interval

2.Yes, because 300 is below the lower limit of the confidence interval

3.No, because 300 is the confidence interval

4.Yes, because 300 is the confidence interval

13. 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 the .05 level of significance, is there evidence that the population mean is above $300?

1.No, because 300 is below the lower limit of the confidence level

2.Yes, because 300 is below the lower limit of the confidence interval

3.No, because 300 is in the confidence interval

4.Yes, because 300 is in the confidence interval

14. Explain the difference between parts A and C. In both parts we are asked whether or not there is evidence that the population mean was over $300.

In part A: x(bar) = $315.40; s = $43.2; Sample size = 25

In part C: x(bar) = $315.40; s = $75; Sample size = 25

1.The larger mean adds uncertainty in the sample. The sample may have had some outliers.

2.The smaller mean adds uncertainty in the sample. The sample may have had some outliers.

3.The larger standard deviation adds uncertainty in the sample. The sample may have had some outliers.

4.The smaller standard deviation add uncertainty in the sample. The sample may have had some outliers.