What is the One Sample Wilcoxon Test? The one sample Wilcoxon test is a hypothesis test to compare the median of one population with a specified value. It is an alternative test of one sample t-test when the distribution of the data is non-normal. It is more powerful than one sample sign test but it assumes […]
What is the One Sample Proportion Test? One sample proportion test is a hypothesis test to compare the proportion of one certain outcome (e.g. the number of successes per the number of trials, or the number of defects per the total number of opportunities) occurring in a population following the binomial distribution with a specified […]
What is Mood’s Median Test? Mood’s median test is a statistical test to compare the medians of two or more populations. The symbol k is the number of groups of our interest and is equal to or greater than two. Mood’s median is an alternative to Kruskal–Wallis. For the data with outliers, Mood’s median test […]
What is the Mann Whitney Test? The Mann Whitney test (also called Mann–Whitney U test or Wilcoxon rank-sum test) is a statistical hypothesis test to compare the medians of two populations that are not normally distributed. In a non-normal distribution, the median is the better representation of the center of the distribution. Where: Mann Whitney […]
What is One Way ANOVA? One way ANOVA is a statistical method to compare means of two or more populations. It is a generalized form of the two sample t-test since a two sample t-test compares two population means and one-way ANOVA compares k population means where k ≥ 2. Assumptions of One Way ANOVA […]
What is a Paired t Test? A Third type of a Two Sample t-Test is the Paired t Test. This test is used when the two populations are dependent of each other, so each data point from one distribution corresponds to a data point in the other distribution. When using a paired t test, the […]
What is Two Sample T Test? Two sample t test is a hypothesis test to study whether there is a statistically significant difference between the means of two populations. Where: μ1 is the mean of one population and μ2 is the mean of the other population of our interest. Assumptions of Two Sample T Tests Three […]
What is a t Test? In statistics, a t test is a hypothesis test in which the test statistic follows a Student’s t distribution if the null hypothesis is true. We apply a one sample t test when the population variance (σ) is unknown and we use the sample standard deviation (s) instead. A hypothesis […]
What is Central Limit Theorem? The Central Limit Theorem is one of the fundamental theorems of probability theory. It states a condition under which the mean of a large number of independent and identically-distributed random variables, each of which has a finite mean and variance, would be approximately normally distributed. Let us assume Y1, Y2 […]
What is Multi Vari Analysis? Multi Vari analysis is a graphic-driven method to analyze the effects of categorical inputs on a continuous output. It studies how the variation in the output changes across different inputs and helps us quantitatively determine the major source of variability in the output. Multi-Vari charts are used to visualize the […]
