The sample size n can be calculated using the following formula. Below is the mathematical illustration for the Taro Yamane method. If the population is N then the corrected sample size should be 186N N185.
In practice the sample size used in a study is usually determined based on the cost time or convenience of collecting the data and.
Factors Contributing To Sample Size Collection. Thus 186 sample size arrived at should be corrected adjusted for finite population. Where n required sample size in each group m1is the mean change in pain score from baseline to week 24 in Drug A 5 m2is the mean change in pain score from baseline to week 24 in Drug B 45 the clinically important difference m1-m2 05 s is the standard deviation 1195. The formula for the sample size can be written mathematically as follows.