Essential Genetics 6th Edition by Daniel Hartl

Exercise 15

What are the values of a chi-square that yield P values of 5 percent (statistically significant) when there are 1, 2, 3, 4, and 5 degrees of freedom? For the goodness-of-fit type of chi-square test illustrated in this chapter, how many classes of data do these degrees of freedom represent? Because the chi-square values regarded as significant increase with the number of degrees of freedom, does this mean that it becomes increasingly "hard" (less likely) to obtain a statistically significant chi-square value when the genetic hypothesis is true?