Concept explainers
For Problems 9-17 assume that the distribution of differences d is mound-shaped and symmetric.
Please provide the following information for Problems 9-17.
(a) What is the level of significance? State the null and alternate hypotheses. Will you use a left-tailed, right-tailed, or two-tailed test?
(b) Check Requirements What sampling distribution will you use? What assumptions are you making? Compute the value of the sample test statistic and corresponding t value.
(c) Find (or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.
(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level
(e) Interpret your conclusion in the context of the application.
In these problems, assume that the distribution of differences is approximately normal.
Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more ‘‘conservative” answer.
Archaeology: Slone Tools The following is based on information taken from Bandelier Archaeological Excavation Project: Summer 1990 Excavations at Burnt Mesa Pueblo and Casa del Rito, edited by T. A. Kohler (Washington State University, Department of Anthropology). The artifact frequency for an excavation of a kiva in Bandelier National Monument gave the following information.
Stratum | Flaked Stone Tools | Nonflaked Stone Tools |
1 | 7 | 3 |
2 | 3 | 2 |
3 | 10 | 1 |
4 | 1 | 3 |
5 | 4 | 7 |
6 | 38 | 32 |
7 | 51 | 30 |
8 | 25 | 12 |
Does this information indicate that there tend to be more flaked stone tools than nonflaked stone tools at this excavation site? Use a 5% level of significance.
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