Concept explainers
A study was performed to determine the effect of introducing a low-fat diet on hormone levels of 73 postmenopausal women not using exogenous hormones [15]. The data in Table 8.25 were presented for plasma estradiol in log10 (picograms/milliliter).
Table 8.25 Change in plasma estradiol after adopting a low-fat diet
aValues are mean and sd (in parentheses) for log (base 10) of preintervention and postintervention measurements and for their difference.
Suppose a similar study is planned among women who use exogenous hormones. How many participants need to be enrolled if the mean change in log10 (plasma estradiol) is −0.08, the standard deviation of change is 0.20, and we want to conduct a two-sided test with an α level of .05 and a power of .80?
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Fundamentals of Biostatistics
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillAlgebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageCalculus For The Life SciencesCalculusISBN:9780321964038Author:GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.Publisher:Pearson Addison Wesley,
- College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage LearningHolt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL