29
Mar
Chi Squared For Dummies. Let me take a shot at explaining the Chi-square test with a focus on intuition rather than the formula. This is the formula for Chi-Square. In fact statistics is a mathematical science even though not a subfield of math. See Chi-Square Test page for more details.
Chi-Square is one of the most useful non-parametric statistics. Chi-squared is actually the square of the Z statistic. If two categorical variables are related in some population. That means that the data has been counted and divided into categories. Chi is a Greek symbol that looks like the letter x as we can see it in the formulas. To calculate the chi-square we will take the square of the difference between the observed value O and expected value E values and further divide it by the expected value.
Σ means to sum up see Sigma Notation O each Observed actual value.
Can only be used for comparison of two proportions. Let me take a shot at explaining the Chi-square test with a focus on intuition rather than the formula. The Chi-Square test is used in data consist of people distributed across categories and to know whether that distribution is different from what would expect by chance. The null hypothesis H o is that the observed frequencies are the same as the expected frequencies except for chance variation. This is the formula for Chi-Square. To calculate the chi-square we will take the square of the difference between the observed value O and expected value E values and further divide it by the expected value.