In: Statistics and Probability
a)Ho: the frequencies for each category are equal
Ha: the frequencies for each category are not equal
b) critical value is chi square with n-1=3-1=2 degrees of freedom and α=0.05, which is 5.991
c) if there were equally distributed , the probabilities for
each would be 1/3,1/3,1/3
So the expected frequencies would be 20,20,20
Chi
square=Σ(observed-expected)2/expected=(29-20)2/20+(20-20)2/20+(11-20)2/20=81/20+81/20=162/20=8.1
d) 8.1>5.9 so we are in the rejection region
we reject the null hypothesis
e) there is significant evidence that the frequencies for categories less than 12, equal to 12 and more than 12 are not equal