Which of the following are TRUE about the class boundaries and cumulative frequencies?  Select all that apply.   Group of answer choices a. The cumulative frequencies are 7 17 28 31 35    b. The class boundaries are 1.5-9.5  9.5-16.5 16.5-23.5 23.5-30.5   30.5-37.5  c. The class boundaries are 1.5-8.5 8.5-15.5 15.5-22.5 22.5-29.5 29.5-36.5 d. The cumulative frequencies are: 7 19 30 33 35  e. The class boundaries are 1.5-9.5 9.5-17.5 17.5, 25.5 25.5-33.5 33.5-41.5