Final answer:
The degrees of freedom for a chi-square goodness-of-fit test with 6 categories is 5. This is computed by taking the number of categories (6) and subtracting one.
Step-by-step explanation:
You are conducting a goodness-of-fit test for a multinomial distribution with 6 categories, and you have collected data from 72 subjects. For this type of test, which falls under the chi-square test, we calculate the degrees of freedom (df) by subtracting 1 from the number of categories. Therefore, the degrees of freedom for your test would be:
df = number of categories - 1
df = 6 - 1
df = 5
So, the degrees of freedom for the χ² distribution for this goodness-of-fit test would be 5. Remember that each category should have an expected value of at least five to effectively use this test, and the test is typically right-tailed.