Question

Researchers wanted to evaluate whether a certain herb improved memory in elderly adults as measured by objective tests. To do​ this, they recruited 85 men and 132 women older than 55 years and in good health. Participants were randomly assigned to receive the​ herb, 45 mg 3 times a​ day, or a matching placebo. A measure of memory improvement was determined by a standardized test of learning and memory. ​(a) What type of experimental design is​ this? ​Matched-pair design Completely randomized design ​(b) What is the population being​ studied? A. All adults B. Adults older than 55 years C. All adults in good health D. Adults older than 55 years and in good health ​(c) What is the response variable in this​ study? A. The score on the standardized test of learning and memory B. The age of the participants in the study C. The 45 mg 3 times a day D. The number of men and women in the study ​(d) What is the​ factor? A. The herb B. The number of men and women in the study C. 45 mg 3 times a day or a matching placebo D. The age and health of the adult What are the​ treatments? A. The number of men and women in the study B. 45 mg 3 times a day or a matching placebo C. The herb D. The age and health of the adult ​(e) Identify the experimental units. Which of the following is​ correct? A. Men and women older than 55 who are in good health B. Elderly adults C. The 85 men and 132 women older than 55 who are in good health that participated in the study D. The placebo and 45 mg of the herb Click to select your answer.

Answer 1