39 a small pilot study is conducted to investigate

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39. A small pilot study is conducted to investigate the effect of a nutritional supplement on total body weight. Six participants agree to take the nutritional supplement. To assess its effect on body weight, weights are measured before starting the supplementation and then after 6 weeks. The data are shown below. Is there a significant increase in body weight following supplementation? Run the test at a 5% level of significance.
40. A small pilot study is run to compare a new drug for chronic pain to one that is currently available. Participants are randomly assigned to receive either the new drug or the currently available drug and to report improvement in pain on a 5-point ordinal scale: 1 = Pain is much worse, 2 = Pain is slightly worse, 3 = No change, 4 = Pain improved slightly, 5 = Pain much improved. Is there a significant difference in self-reported improvement in pain? Use the Mann-Whitney U test with a 5% level of significance.
41. The following table was presented in an article summarizing a study to compare a new drug to a standard drug and to a placebo. Characteristic* New Drug Standard Drug Placebo p Age, years 45.2 (4.8) 44.9 (5.1) 42.8 (4.3) 0.5746 % Female 51% 55% 57% 0.1635 Annual Income, $000s 59.5 (14.3) 63.8 (16.9) 58.2 (13.6) 0.4635
% with Insurance 87% 65% 82% 0.0352 Disease Stage 0.0261 Stage I 35% 18% 33% Stage II 42% 37% 47% Stage III 23% 51% 20% *Table entries and Mean (SD) or % Are there any statistically significant differences in the characteristics shown among the treatments? Justify your answer 42. What is the appropriate statistical test to assess whether there is an association between obesity status (normal weight, overweight, obese) and 5-year incident cardiovascular disease (CVD)? Suppose each participant’s obesity status (category) is known along with whether they develop CVD over the next 5 years or not. 43. A random sample of 8 adults aged 30 years were asked how much they spent on medical costs in the year 2009. Using the following data, compute the sample mean, the sample standard deviation, the sample median, and the first and third quartiles.
44. The table below summarizes baseline characteristics of patients participating in a clinical trial. a) Are there any statistically significant differences in baseline characteristics between treatment groups? Justify your answer. P

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