3. (20 points) A researcher is interested in whether the phonics method of teaching reading is more or less effective than the sight method, depending on what grade the child is in. Twenty children were randomly selected from each of 3 grades - 1st, 2nd, and 3rd (total N = 60), then randomly assigned to one of the 2 teaching methods (so there were 30 children exposed to each teaching method). Mean reading achievement scores (higher scores indicating greater comprehension) for each grade-teaching method combination were (each cell has n = 10) Sight Method Phonics Method 1st Grade 17.8 2nd Grade 30.2 3rd Grade 47 21.4 37.8 36.8 = SS 634.8 SS method 1.67 SS grade = 511.37 SS method x grade = 872.13 Use a = .05 as the standard for testing all effects. Explain the results in layperson's terms.