Calculate the degrees of freedom and the critical values, or cutoffs, assuming a two-tailed test with a p level of 0.05, for each of the following designs: 

a. Forty students were recruited for a study about the relation between knowledge regarding academic integrity and values held by students, with the idea that students with less knowledge would care less about the issue than students with more knowledge. 

b. Twenty-seven couples are surveyed regarding their years together and their relationship satisfaction.