Range of ankle motion is a contributing factor to falls among the elderly. Suppose a team of researchers is studying how combining compression bandages or compression hosiery with different types of footwear affects range of ankle motion. They suspect that more than half of all adults wearing compression bandages and no shoes will see decrease in range of ankle motion of at least 2° compared to when they are not wearing compression bandages or compression hosiery and are barefoot. They collect sample data from a random sample of 29 adults and determine that 17 see such a decrease in range of ankle motion. They compute a sample proportion of 17 = 0.586 %3D 29 The researchers conduct a one-sample z-test for a proportion, testing Ho : p = 0.500 against H1 : p > 0.500, where p is the proportion of adults whose range of angle motion decreases at least 2° while wearing compression bandages with no shoes. The lower limit of a 95% confidence interval for p is 0.436. Based on this interval, what should the researchers conclude about their z-test? The researchers should fail to reject Ho at a significance level of a = 0.10 - because || 0.586 > 0.436| a = 0.95 0.500 > 0.436 να=0. 10 v 0.586 > 0.436 0.586 > 0.500 a = 0.05

The data from an independent-measures research study produce a sample mean difference of 4 points, and each sample has a variance of 10. If there are n = 20 scores in each sample, then what is the estimated standard error of the difference between means?

Hutchinson-Gilford progeria syndrome is a rare genetic condition that produces rapid aging in children. In individuals with this syndrome, cardiovascular disease is a common cause of death in the teenage years. A clinical study examined the effect of treatment with the drug lonafarnib on a number of physiological outcomes. The researchers measured the pulse wave velocity (PWV) of 18 children diagnosed with progeria and recruited worldwide. The study reports that the mean PWV of 18 children diagnosed with progeria is 12.44 m/s, and the standard deviation is 3.638 m/s. Assuming that PWV is normally distributed, is there significant evidence that the mean PWV of children with progeria is abnormally high (i.e. greater than 6.6 m/s)? Let �  (pronounced as "mu") be the true mean PWV of children with progeria.  What are the two competing hypotheses?       ["", "", "", ""]  What is the test statistic?       ["", "", "", ""]  What is the p value?       ["", "", "", ""]  What is the rejection…

In a study performed on comfort food eating during times of stress, it was found that mean rated comfort food consumption level (on a scale from 1-20) for a group of students undertaking their exam period was 14.  In comparison, a group of students who were not undertaking exams or examination preparation had a mean rated comfort food consumption level of 10.  The pooled estimate of the population variance was 64.  What is the estimated effect size (d) of the study?       0.80       0.06       0.50       2.00

Researchers have noted a decline in cognitive functioning as people age (Bartus, 1990). However, the results from other research suggest that the antioxidants in foods such as blueberries may reduce and even reverse these age-related declines (Joseph et al., 1999). To examine this phenomenon, suppose that a researcher obtains a sample of n = 16 adults who are between the ages of 65 and 75. The researcher uses a standardized test to measure cognitive performance for each individual. The participants then begin a 2-month program in which they receive daily doses of a blueberry supplement. At the end of the 2-month period, the researcher again measures cognitive performance for each participant. The results show an average increase in performance of MD = 7.4 with SS = 1215. Does this result support the conclusion that the antioxidant supplement has a significant effect on cognitive performance? Use a two-tailed test with α = .05. Show your computations.

The Wall Street Journal asked Concur Technologies, Inc., an expense management company, to examine data from 8.3 million expense reports to provide insights regarding business travel expenses. Their analysis of the data showed that New York was the most expensive city. The following table shows the average daily hotel room rate (X) and the average amount spent on entertainment (Y) for a random sample of 9 of the 25 most-visited U.S. cities. These data lead to the estimated regression equation y = 17.49 + 1.0334x. For these data SSE = 1541.4. Use Table 1 of Appendix B.  a. Predict the amount spent on entertainment for a particular city that has a daily room rate of $89 (to 2 decimals). b. Develop a 95% confidence interval for the mean amount spent on entertainment for all cities that have a daily room rate of $89 (to 2 decimals). c. The average room rate in Chicago is $128. Develop a 95% prediction interval for the amount spent on entertainment in Chicago (to 2 decimals).