14 13 12 11 10- HB SC HB SS HB ST Type Hemoglobin level

A 1-1 matched case-control study was conducted among office workers on the association between suffering chronic lower back pain and sitting at a PC. There were 118 cases (suffering from back pain), individually matched to controls (not suffering from back pain) on sex, age, and general exercise habits. The exposure was the amount of time spent at a PC. The data are in Table 1: Case > 4 hours/day 4 hours/day 18 13 <4 hours/day 25 62 Use a suitable test to test for no association between suffering chronic lower back pain and time spent sitting at a PC.

The medical researcher is comparing two treatments for lowering cholesterol: diet and meds. The researcher wants to see if the patients who receive the recommendation to change their diet have less success lowering cholesterol compared to a prescription of meds. A random sample of some patients who received the recommendation to change their diet and others who were prescribed meds was taken. The results of how many did or did not lower their cholesterol are shown below: Data on Diet vs. Meds for Weight Los Diet Meds Yes 416 483 No 266 248 What can be concluded at the a = 0.05 level of significance? %3D For this study, we should use Select an answer a. The null and alternative hypotheses would be: Ho: Select an answer > Select an answer Select an answer O (please enter a decimal) Hj: Select an answer Select an answer Select an answer O (Please enter a decimal) b. The test statistic ? O (please show your answer to 3 decimal places.) c. The p-value = (Please show your answer to %3D 4…

2. A researcher had rats engage in a lever-press task for either a small, medium, or larger reward. The number of lever presses was the dependent variable. The data were as follows: Reward Size Small Medium Large 1 4 6 4 3 5 1 4 4 2 5 T = 13 SS = 2.75 T= 6 T= 20 SS = 9 SS = 2 EX2 = 165 a. Do the data indicate that reward size had a significant impact on lever-pressing? Use the hypothesis testing steps & p = .05. Compute any necessary post-hoc tests. b. Compute eta-squared to measure the effect size.

A Journal published longitudinal study of hearing impairment in a group of elderly patients with intellectual disabilities. The hearing function of each patient was screened each year over a 10 - year period. At the study's conclusion, the hearing loss of each patient was categorized as severe, moderate, mild, or none. The classification of the 28 surviving patients are summarized in the following table. Hearing loss          Number of Patients  None                      7 Mild                        7 Moderate               9 Severe                    5 Total                      28 Conduct a test to determine whether the trueproportions of intellectually disabled elderly patients in each ofthe hearing-loss categories differ. Use a 5% significance level.   We are doing this on a Ti84 plus Calculator.

PETROGAS is testing new filters for its motorbikes. One brand of filter (Filter A) is placed in one motorbike, and the other brand (Filter B) is placed in the second motorbike. Random samples of air released from the motorbikes are taken at different times throughout the day. Pollutant concentrations are measured for both motorbikes at the same time. The following data attached represent the pollutant concentrations (in parts per million) for samples taken at 20 different times after passing through the filters. a. Test the hypothesis that the mean for the pollutant concentration for Filter B is greater than 30. Use the 1% level of significance. b. Construct a 95% confidence interval for the difference in mean pollutant concentration, where a difference is equal to the pollutant concentration passing through Filter A minus the passing through Filter B. c. Using the 5% significance level, determine whether there is evidence that mean for the pollutant concentration for Filter A…

A team of epidemiologists at the Mayo Clinic wanted to find whether there is an association between obesity and cardiovascular disease (CVD). They conducted a prospective cohort study following obese and non-obese individuals who were free of CVD at the beginning of study for five years. The investigators were also interested in assessing age as a potential confounder, effect modifier, or both. Use the data below to answer the accompanying questions.     CVD No CVD Total Obese 10 90 100 Not Obese 35 465 500 Total 45 555 600       CVD No CVD Total Obese 36 164 200 Not Obese 25 175 200 Total 61 339 400   1. Compute the appropriate measure of association for those who were less than age 50.  2. Compute the appropriate measure of association for those who were older or equal to age 50.  3. Compute the crude measure of association?  4. List three attributes that age must satisfy before it could…

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).