The number of subjects needed for a study _____.
A)is determined by a mathematical formula and should be as small as possible
B)should be large enough to exclude differences between the control and experimental groups due to chance
C)should be kept small so that the data are manageable and there is less room for statistical error
D)is determined by a mathematical formula and should be large enough to exclude differences between the control and experimental groups due to chance
E)is determined by randomization and therefore,can be scaled as needed

Question

The number of subjects needed for a study _____.​
A)​is determined by a mathematical formula and should be as small as possible
B)should be large enough to exclude differences between the control and experimental groups due to chance
C)should be kept small so that the data are manageable and there is less room for statistical error
D)is determined by a mathematical formula and should be large enough to exclude differences between the control and experimental groups due to chance
E)​is determined by randomization and therefore,can be scaled as needed

Quizplus · Accepted Answer

The number of subjects needed for a study is determined by a mathematical formula and should be large enough to exclude differences between the control and experimental groups due to chance. This is done to ensure that the results are statistically significant and not due to random variation. Option A and C are incorrect as they suggest that the sample size should be kept small, which can lead to less reliable results. Option B is partially correct, but it doesn't mention the importance of statistical significance. Option E is incorrect as randomization alone cannot determine the appropriate sample size for a study.

The Number of Subjects Needed for a Study _____