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Z-test tests the mean of a distribution. For each significance level in the confidence interval, the Z-test has a single critical value (for example, 1.96 for 5% two tailed) which makes it more convenient than the Student's t-test whose critical values are defined by the sample size (through the corresponding degrees of freedom). Both the Z ...
where R 1 = N 11 + N 12 + N 13, and C 1 = N 11 + N 21, etc. . The trend test statistic is = (), where the t i are weights, and the difference N 1i R 2 −N 2i R 1 can be seen as the difference between N 1i and N 2i after reweighting the rows to have the same total.
Comparison of the various grading methods in a normal distribution, including: standard deviations, cumulative percentages, percentile equivalents, z-scores, T-scores. In statistics, the standard score is the number of standard deviations by which the value of a raw score (i.e., an observed value or data point) is above or below the mean value of what is being observed or measured.
Stata (/ ˈ s t eɪ t ə /, [2] STAY-ta, alternatively / ˈ s t æ t ə /, occasionally stylized as STATA [3] [4]) is a general-purpose statistical software package developed by StataCorp for data manipulation, visualization, statistics, and automated reporting.
[Note 1] Descriptive statistics Nonparametric statistics Quality control Survival analysis Data processing Base stat. [Note 2] Normality tests [Note 3] CTA [Note 4] Nonparametric comparison, ANOVA: Cluster analysis Discriminant analysis BDP [Note 5] Ext. [Note 6]
where t is a random variable distributed as Student's t-distribution with ν − 1 degrees of freedom. In fact, this implies that t i 2 /ν follows the beta distribution B(1/2,(ν − 1)/2). The distribution above is sometimes referred to as the tau distribution; [2] it was first derived by Thompson in 1935. [3]
Data management, including input from standard sources (such as Excel), transformations and sample controls [2] Programming language, matrix algebra package and scientific calculator [1] Random number generation, matrix for bootstrapping, Gibbs sampling and Monte Carlo simulation [1] Graphical and numeric descriptive statistics analysis [1]
In some applications, the observations within each pair can only take the values 0 or 1. For example, 0 may indicate failure and 1 may indicate success. There are 4 possible pairs: {0,0}, {0,1}, {1,0}, and {1,1}. In these cases, the same procedure as the sign test is used, but is known as McNemar's test. [6]