An article in the journal Applied Nutritional Investigation reported the results of a comparison of two different weight-loss programs (Liao, 2007). In the study, obese participants were randomly assigned to one of two groups and the percent of body fat loss was recorded. The soy group, a low-calorie group that ate only soy-based proteins (M= 2.30, s=0.55) , while the traditional group, a low-calorie group that received 2/3 of their protein from animal products and 1/3 from plant products (M= 1.22, s=0.50). If sM1–M2 = 0.3, s2pooled = 0.275, n1 = 6, n2 = 6 is there a difference between the two diets. Use alpha of .05 anda two-tailed test to complete the 4 steps of hypothesis testing.

Serum estradiol is an important risk factor for breast cancer in postmenopausal women. To better understand the etiology of breast cancer, serum-estradiol samples were collected from 25 premenopausal women (at about the same time period of the menstrual cycle) of whom 10 were Caucasian and 15 were African American. The data are shown in Table 7.3. The distribution of serum estradiol is usually highly skewed (especially for premenopausal women), and we are reluctant to assume normality. Table 7.3 Serum estradiol and ethnicity in 25 premenopausal women, where 0=Caucasian and 1=African-American. ID Serum_estradiol Ethic 1 94 0 2 54 1 3 31 0 4 21 1 5 46 1 6 56 0 7 18 1 8 19 1 9 12 1 10 14 0 11 25 0 12 35 1 13 22 1 14 71 0 15 43 1 16 35 1 17 42 1 18 50 1 19 44 1 20 41 0 21 28 0 22 65 0 23 31 0 24…

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.

In a certain study, the effect on oat yield was compared for the Pallinup, Overberg and Magnifico varieties of oats and four different concentrations of manure (0, 0.2, 0.4 and 0.6 tonnes per acre). Identify the experimental units, response variable, factor(s), levels of each factor and treatments.

You also conducted a review of the research literature and found that similar studies examining the relationship between alcohol consumption and liver cancer found the following: Smithson et al. RR 3.3 (95% CI:1.95-5.20)  Ribera et al. RR 2.1 (95% CI:1.17-3.33)  Gonzalez et al. RR 2.75 (95% CI 2.26-3.45) Which one of Hill’s criteria does this illustrate? Explain.

Roediger and Karpicke (2006) investigated whether the test-enhanced learning effect (the demonstration that repeated testing improves memory for material) was due merely to repeated exposure to material. They randomly assigned participants to one of two conditions(study-study or study-test) and to one of three interval conditions (final test at a delay of 5 minutes, 2 days, or 1 week). The dependent variable was the proportion of idea units recalled for an encyclopedia. How should this be labeled? a. 4x2 between-groups ANOVA b. 2x2 within-groups ANOVA c. 2x3 within-groups ANOVA d. 2x3 between-groups ANOVA

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).