Vitamin E and the Risk of Prostate Cancer: Klien et al (2011) conducted the following study to determine the effect of vitamin E and selenium treatment on the risk of developing prostate cancer in healthy men. A total of 34,887 men from different study sites in the United States, Canada, and Puerto Rico were randomly selected. To be eligible to participate, the men had to take a rectal examination that showed he was not suspicious of having prostate cancer and be aged 50 years or older for black men and 55 years or older for all others. Each man was randomly assigned to receive one of four treatments: selenium, vitamin E, selenium and vitamin E together, or a placebo. The men were followed up after 8 years to see if they had developed prostate cancer or not. The main question of interest is to determine if the risk of developing prostate cancer differs by the treatment taken. The data are summarized in the table below:

For a two-factor ANOVA with two levels of factor A, two levels of factor B, and a separate sample of n = 5 participants in each treatment condition, the two means for level A1 are 6 and 8, and the two means for level A2 are 6 and 10. For these data, what is the value of SSB?

Travelers who have no intention of showing up often fail to cancel their hotel reservations in a timely manner.  These        travelers are known, in the parlance of the hospitality trade, as “no-shows”.  To protect against no-shows and late        cancellations, hotels invariably overbook rooms.  A recent study examined the problems of over-booking rooms in the hotel        industry.  The following data, extracted from the study represent the daily numbers of late cancellations and no-shows for a        random sample of 10 days at a hotel:     18, 16, 16, 16, 14, 18, 16, 18, 14, 19.   a)    Compute s, the sample s.d. for the data set

The Joint Commission on Accreditation of Healthcare Organizations mandated that hospitals ban smoking by 1994. To study the effects of this ban on smoking behaviors, subjects were randomly selected from two different populations: those from hospitals with the ban and those from hospitals without the ban. Investigators were interested in determining if this smoking ban had any impact on the proportion of smokers employed at each hospital that then quit smoking.  Among 843 smoking employees of hospitals with the smoking ban, 56 quit smoking during the study period. Among 703 smoking employees from workplaces without the smoking ban, 27 quit smoking during the study period. Below is the Stata output that was run to determine if there was a statistically significant difference between these two proportions at the α=0.05 level. A. What is the estimate of the proportion of smokers from the hospitals that implemented the ban that quit smoking (the blank labeled "C" in the above output)?…

For a two-factor ANOVA with two levels of factor A, two levels of factor B, and a separate sample of n = 8 participants in each treatment condition, the two means for level A1 are 3 and 5, and the two means for level A2 are 4 and 2. For these data, what is the value of SSbetween treatments?

A certain HMO is attempting to show the benefits of managed care to an insurance company. The HMO believes that certain types of doctors are more cost-effective than others. One theory is that certification level is an important factor in measuring the cost-effectiveness of physicians. To investigate this, the HMO obtained independent random samples of 27 physicians from each of the three certification levels-Board certified (C): Uncertified, board eligible (E); and Uncertified, board ineligible (1)- and recorded the total per member per month charges for each (a total of 81 physicians). How many factors are present in this study? 0000 81 27 3 01

A 2012 article in the New England Journal reports the results of a randomized trial to assess the association between regular usage of asthma medication prior to turning 18 years old, and height at age 18 years. As per the authors, "From December 1993 through September 1995, we randomly assigned 1041 children between the ages of 5 and 13 years with mild-to-moderate asthma to one of three study groups in the double-blind, placebo-controlled CAMP trial." (reference: Kelly H, et al. Effect of Inhaled Glucocorticoids in Childhood on Adult Height. New England of Medicine (2012). 367 (10)) The random assignment groups were Budesonide, Nedocromil and placebo. The following graphic shows the distribution of female and male participant heights at different times in the study follow-up, presented for the Budesonide and placebo samples. A Unadjusted Height Distribution 200 I Budesonide I Placebo 190 180- 170- 160- 150- 140- 130- 120- 110- 100- 0- Trial entry 2 Yr Trial end Adult Trial entry 2 Yr…

Researchers are investigating whether people who exercise with a training partner have a greater increase, on average, in targeted exercise intensity compared with people who exercise alone. Two methods of collecting data have been proposed. Method I: Recruit volunteers who are willing to participate. Randomly assign each participant to exercise with a training partner or to exercise alone. Method II: Select a random sample of people from all the people who exercise at a community fitness center. Ask each person in the sample whether they use a training partner, and use the response to create the two groups. (a) For each method, the researchers will record the change in targeted exercise intensity for each person in the investigation. They will compare the mean change in intensity between those who exercise with a training partner and those who do not. (i) Describe the population of generalization if method I is used. Explain your answer. (ii) Describe the population of…

Acne is a common skin disease that affects most adolescents and can continue into adulthood. A study compared the effectiveness of three acne treatments and a placebo, all in gel form, applied twice daily for 12 weeks. The study's 517 teenage volunteers were randomly assigned to one of the four treatments. Success was assessed as clear or almost clear skin at the end of the 12 week period. The results of the study can be seen in the table below. Using the appropriate statistical test, determine if there is significant evidence that the four treatments perform differently. If so, how do they compare.

Based on the graphic, what is the approximate range of individual height values at trial entry for females in the Budesonide group? 108 cm to 133 cm 124 cm to 146 cm 108 cm to 163 cm 133 cm to 163 cm