Final answer:
In a chi-square test, when the observed values deviate significantly from the expected values, the null hypothesis is rejected.
Step-by-step explanation:
When the observed values (O) deviate significantly from the expected values (E) in a chi-square test, it means that the null hypothesis is rejected. The chi-square test is used to determine if there is a significant association between two categorical variables. If the observed values differ significantly from the expected values, it suggests that there is a relationship between the variables.