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  2. Z-test - Wikipedia

    en.wikipedia.org/wiki/Z-test

    Difference between Z-test and t-test: Z-test is used when sample size is large (n>50), or the population variance is known. t-test is used when sample size is small (n<50) and population variance is unknown. There is no universal constant at which the sample size is generally considered large enough to justify use of the plug-in test. Typical ...

  3. Sample size determination - Wikipedia

    en.wikipedia.org/wiki/Sample_size_determination

    The table shown on the right can be used in a two-sample t-test to estimate the sample sizes of an experimental group and a control group that are of equal size, that is, the total number of individuals in the trial is twice that of the number given, and the desired significance level is 0.05. [4]

  4. List of statistical tests - Wikipedia

    en.wikipedia.org/wiki/List_of_statistical_tests

    Download as PDF; Printable version; In other projects ... small sample size [10] Mann–Whitney ... Normality test: sample size between 3 and 5000 ...

  5. Cohen's h - Wikipedia

    en.wikipedia.org/wiki/Cohen's_h

    It can be used in calculating the sample size for a future study. When measuring differences between proportions, Cohen's h can be used in conjunction with hypothesis testing . A " statistically significant " difference between two proportions is understood to mean that, given the data, it is likely that there is a difference in the population ...

  6. Fisher transformation - Wikipedia

    en.wikipedia.org/wiki/Fisher_transformation

    The application of Fisher's transformation can be enhanced using a software calculator as shown in the figure. Assuming that the r-squared value found is 0.80, that there are 30 data [clarification needed], and accepting a 90% confidence interval, the r-squared value in another random sample from the same population may range from 0.656 to 0.888.

  7. Efficiency (statistics) - Wikipedia

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

    For comparing significance tests, a meaningful measure of efficiency can be defined based on the sample size required for the test to achieve a given task power. [ 14 ] Pitman efficiency [ 15 ] and Bahadur efficiency (or Hodges–Lehmann efficiency ) [ 16 ] [ 17 ] [ 18 ] relate to the comparison of the performance of statistical hypothesis ...

  8. Alcohol is not good for us. 5 tips to stay safe(r) if you drink

    www.aol.com/drink-not-drink-5-tips-142139741.html

    Editor’s note: The podcast Chasing Life With Dr. Sanjay Gupta explores the medical science behind some of life’s mysteries big and small. You can listen to episodes here. (CNN) — The ...

  9. Ratio estimator - Wikipedia

    en.wikipedia.org/wiki/Ratio_estimator

    where N is the population size, n is the sample size, m x is the mean of the x variate and s x 2 and s y 2 are the sample variances of the x and y variates respectively. These versions differ only in the factor in the denominator (N - 1). For a large N the difference is negligible.