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Sample size determination or estimation is the act of choosing the number of observations or replicates to include in a statistical sample. The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample. In practice, the sample size used in a study is usually determined ...
Power (statistics) In frequentist statistics, power is a measure of the ability of an experimental design and hypothesis testing setup to detect a particular effect if it is truly present. In typical use, it is a function of the test used (including the desired level of statistical significance ), the assumed distribution of the test (for ...
Informally, in frequentist statistics, a confidence interval ( CI) is an interval which is expected to typically contain the parameter being estimated. More specifically, given a confidence level (95% and 99% are typical values), a CI is a random interval which contains the parameter being estimated % of the time. [ 1][ 2] The confidence level ...
Randomness test. A randomness test (or test for randomness ), in data evaluation, is a test used to analyze the distribution of a set of data to see whether it can be described as random (patternless). In stochastic modeling, as in some computer simulations, the hoped-for randomness of potential input data can be verified, by a formal test for ...
v. t. e. In probability theory, the sample space (also called sample description space, [ 1] possibility space, [ 2] or outcome space[ 3]) of an experiment or random trial is the set of all possible outcomes or results of that experiment. [ 4] A sample space is usually denoted using set notation, and the possible ordered outcomes, or sample ...
x̅ and s chart. x̅. and s chart. In statistical quality control, the and s chart is a type of control chart used to monitor variables data when samples are collected at regular intervals from a business or industrial process. [1] This is connected to traditional statistical quality control (SQC) and statistical process control (SPC).
The ratio estimator is a statistical estimator for the ratio of means of two random variables. Ratio estimates are biased and corrections must be made when they are used in experimental or survey work. The ratio estimates are asymmetrical and symmetrical tests such as the t test should not be used to generate confidence intervals.
The program can generate graphs of the relationships between power, sample size and the detectable alternative hypothesis. It can plot graphs of any two of these variables while holding the third constant. Linear or logarithmic axes may be used and multiple curves can be plotted on each graph. Graphs may be copied and pasted into other ...