Chi Square Test Statistic. χ 2 i 1 r c o i e i 2 e i under the null hypothesis and certain conditions discussed below the test statistic follows a chi square distribution with degrees of freedom equal to r 1 c 1 where r is the number of rows and c is the number of columns. The data used in calculating a chi square statistic must be random raw mutually exclusive drawn.
The pearson chi square statistic χ 2 involves the squared difference between the observed and the expected frequencies. Pearson s chi squared test is used to determine whether there is a statistically significant difference between the expected frequencies and the. The chi square test is used to check how well the observed values for a given distribution fits with the distribution when the variables are independent.
The pearson chi square statistic χ 2 involves the squared difference between the observed and the expected frequencies.
This is why it is also known as the goodness of fit test. Frac 6 5 4 2 5 4 23 57. A chi square χ2 statistic is a test that measures how a model compares to actual observed data. A chi square test is a test of statistical significance for categorical variables.
