Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

A z-test is statistical test used to determine whether two population means are different when the variances are known and the sample size is large. What Is a Z-Test? A z-test is a statistical test ...

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 ...

The expectations of order statistics of a logarithmic-normal distribution are expressed as functions which are linear in a location and a scale parameter but nonlinear in a shape parameter of the ...

Statistics is a branch of math that involves the collection, description, analysis, and inference of conclusions from quantitative data. But what is a statistic? Let’s find out. The word statistic is ...