We present a simple sample-size formula for weighted log-rank statistics applied to clustered survival data with variable cluster sizes and arbitrary treatment assignments within clusters. This ...

In epidemiologic studies and disease prevention trials, interest often involves estimation of the relationship between some disease endpoints and individual exposure. In some studies, due to the ...

In your school life, you have learned about average and the method to calculate it. The formula to calculate the average is very simple. You just have to add all the values in the given data and ...