The principal of paul revere high school bragged that his 2016 graduating class of 1500 students achieved impressive scores on their act exams. he announced that an "astounding" 36% of the class got a score of 29 or higher, 54% got a score of 21 to 28, and only 10% less than 21. you want to test whether these act results are really that astounding. you visit the act website to see that the national results are 34% getting a score over 28, 58% getting 21 to 28, and 8% less than 21. test whether or not the principal is correct to brag that his proportions were more impressive than the national performance. use an alpha of .05. what are the degrees of freedom for this test?