'How large a sample do I need?' is one of the most commonly asked questions of a statistician. It is also one of the hardest questions to answer. The researcher posing the query usually believes, ...

What is a one sample t test? The t test is a commonly used hypothesis test in statistics that allows us to compare the mean value of a group of sampled data with some hypothesized value, usually a ...

Finite sample breakdown points are obtained for two classes of projection based multivariate location and scatter statistics: the Stahel-Donoho statistics and the Maronna-Yohai statistics. The ...

It's not feasible to contact every member of the population, so only a sample, or a subset, of that population is included when conducting statistical research. The assumption is that the sample is ...

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 ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Dr. JeFreda R. Brown is a financial ...