Question

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

Answer 1

Answer: $\chi^2$ test statistic.

Step-by-step explanation:

The chi-square ($\chi^2$  ) 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 $\chi^2$ test statistic.