7.38 Teaching descriptive statistics. A study compared five
different methods for teaching descriptive statistics. The five
methods were traditional lecture and discussion, programmed
textbook instruction, programmed text with lectures, computer
instruction, and computer instruction with lectures. 45 students
were randomly assigned, 9 to each method. After completing the
course, students took a 1-hour exam. (a) What are the hypotheses
for evaluating if the average test scores are different for the
different teaching methods? (b) What are the degrees of freedom...