enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Sample size determination - Wikipedia

    en.wikipedia.org/wiki/Sample_size_determination

    Learn how to choose the number of observations or replicates in a statistical sample based on various factors, such as confidence level, margin of error, and variability. Find formulas and examples for estimating proportions, means, and variances.

  3. Standard error - Wikipedia

    en.wikipedia.org/wiki/Standard_error

    Learn the definition, formula, and applications of standard error, a measure of the dispersion of sample means around the population mean. Find out how to estimate ...

  4. Ordinary least squares - Wikipedia

    en.wikipedia.org/wiki/Ordinary_least_squares

    Ordinary least squares (OLS) is a method of estimating parameters in a linear regression model by minimizing the sum of squared residuals. Learn the formula, properties, assumptions, and applications of OLS in statistics and econometrics.

  5. Power (statistics) - Wikipedia

    en.wikipedia.org/wiki/Power_(statistics)

    According to this formula, the power increases with the values of the effect size and the sample size n, and reduces with increasing variability . In the trivial case of zero effect size, power is at a minimum ( infimum ) and equal to the significance level of the test α , {\displaystyle \alpha \,,} in this example 0.05.

  6. Unbiased estimation of standard deviation - Wikipedia

    en.wikipedia.org/wiki/Unbiased_estimation_of...

    Correction factor versus sample size n.. When the random variable is normally distributed, a minor correction exists to eliminate the bias.To derive the correction, note that for normally distributed X, Cochran's theorem implies that () / has a chi square distribution with degrees of freedom and thus its square root, / has a chi distribution with degrees of freedom.

  7. Ratio estimator - Wikipedia

    en.wikipedia.org/wiki/Ratio_estimator

    where n is the sample size and N is the population size and s xy is the ... The sample estimate was 71,866.333 baptisms per year over this period giving a ratio of ...

  8. Estimator - Wikipedia

    en.wikipedia.org/wiki/Estimator

    An estimator is a rule for calculating an estimate of a given quantity based on observed data. Learn about the different types, properties and applications of estimators in statistics and decision theory.

  9. Kaplan–Meier estimator - Wikipedia

    en.wikipedia.org/wiki/Kaplan–Meier_estimator

    A plot of the Kaplan–Meier estimator is a series of declining horizontal steps which, with a large enough sample size, approaches the true survival function for that population. The value of the survival function between successive distinct sampled observations ("clicks") is assumed to be constant.