what is the symbol for observed frequency?
Formula 14-1. Equation for chi square (used for both the goodness-of-fit test and the chi-square test of independence [significance]) O stands for the observed frequencies, and E stands for the expected frequencies. Formula 14-2. Equation for finding expected frequencies for the chi-square test of independence if there is no other basis for determining them. RT stands for the row total for a given cell, and CT stands for the column total for the same cell. Formula 14-3.