Question

A researcher reports that her obtained chi square of -17.56 is significant because it exceeds the critical chi square of -3.841 for an alpha of .05 with 2 degrees of freedom. What mistake has been made

1. thanhcong
The mistake that the researcher made is that; neither critical nor obtained Chi squares can have negative values

### How to check the chi – square statistic?

A chi-square statistic is one way to show a relationship between two categorical variables. In statistics, there are two types of variables: numerical (countable) variables and non-numerical (categorical) variables.
The chi-squared statistic is a single number that tells you how much difference exists between your observed counts and the counts you would expect if there were no relationship at all in the population.
Now, Chi square (χ²) is the sum of a set of squared values, and as such it can never be negative. The minimum chi – squared value would be obtained if each Z = 0 so that χ² would also be 0. There is no upper limit to the χ² value. Similarly, the critical chi square cannot also be negative.
Thus, we can conclude that the mistake that the researcher made is that neither critical nor obtained Chi squares can have negative values