A chi-square goodness-of-fit-test is to be used to determine if data fit a Poisson distribution.The data is divided into "k" categories.The mean number of occurrences is unknown and must be estimated.The degrees of freedom for this test would be:
A)k - 1
B)k - 2
C)k - 3
D)k - 4

Question

Quizplus · Accepted Answer

In a chi-square goodness-of-fit test for Poisson distribution, the degrees of freedom is calculated by subtracting the number of estimated parameters from the number of categories. For a Poisson distribution, the parameter is the mean which needs to be estimated from the data. Therefore, in this case, the number of estimated parameters is 1 (the mean) and the number of categories is k. Hence, the degrees of freedom would be k - 1 -1 = k - 2. Therefore, the best choice is B.

A Chi-Square Goodness-Of-Fit-Test Is to Be Used to Determine If