When determining how well an observed set of frequencies fits an expected set of frequencies, what is the test statistic

test statistic.

Step-by-step explanation:

The chi-square (  ) test is a non-parametric statistical test(also known as Goodness of fit test) which is used to determine if a distribution of observed frequencies differs from the expected frequencies.

Chi-square statistic uses either nominal (categorical) or ordinal level data.

Hence, When determining how well an observed set of frequencies fits an expected set of frequencies, the test statistic is test statistic.