Concept explainers
In anthropological studies, an important characteristic of fossils is cranial capacity. Frequently skulls are at least partially decomposed, so it is necessary to use other characteristics to obtain information about cranial capacity. One measure that has been used is the length of the lambda-opisthion chord. The article “Vertesszollos and the Presapiens Theory” (American Journal of Physical Anthropology [1971]) reported the accompanying data for n = 7 Homo erectus fossils.
Suppose that from previous evidence, anthropologists had believed that for each 1-mm increase in chord length, cranial capacity would be expected to increase by 20 cm 3. Do the data given here strongly contradict prior belief?
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Chapter 13 Solutions
Introduction To Statistics And Data Analysis
- A large research project showed that in a sample of 750 adults, 60 of them experienced a midlife crisis . Use this data to test the claim that the percentage of adults who experienced midlife crisis is less than 10%. Use (alpha)= 0.05 .arrow_forwardNext, given a situation in which a research reports a large eta squared effect size (eta squared = .64), why might their reported t value be small and not statistically significant? What may be inference from such a situation? Indicate and provide examples of three of the factors that influence the size of t.arrow_forwardThe authors of the article "Adjuvant Radiotherapy and Chemotherapy in Node-Positive Premenopausal Women with Breast Cancer"† reported on the results of an experiment designed to compare treating cancer patients with chemotherapy only to treatment with a combination of chemotherapy and radiation. Of the 154 individuals who received the chemotherapy-only treatment, 76 survived at least 15 years, whereas 98 of the 164 patients who received the hybrid treatment survived at least that long. With p1 denoting the proportion of all such women who, when treated with just chemotherapy, survive at least 15 years and p2 denoting the analogous proportion for the hybrid treatment, p̂1 = (rounded to three decimal places) and p̂2 = (rounded to three decimal places). A confidence interval for the difference between proportions based on the traditional formula with a confidence level of approximately 99% is 0.494 − 0.598 ± (2.58) (0.494)(0.506) 154 + (0.598)(0.402) 164…arrow_forward
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