The first thing any scientist does before performing an experiment is to form a hypothesis about the experiment's outcome. This often takes the form of a null hypothesis, which is a statistical ...

In the Neyman-Pearson theory of hypothesis testing it is customary to calculate significance levels and power functions on the assumption that the sample size is fixed. The main purpose of this paper ...

Lucas Downey is the co-founder of MoneyFlows, and an Investopedia Academy instructor. Gordon Scott has been an active investor and technical analyst or 20+ years. He is a Chartered Market Technician ...

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Yarilet Perez is an experienced multimedia journalist and fact-checker with a Master of ...