All pieces of data for seventh grade classes are larger than that of any kindergarten class on the table. This also proves with the mean provided.
The MAD, mean absolute deviation, helps you to identify the variation. The MAD for seventh grade was significantly larger than that of the kinder classes. The range for both sets of data is two times one another, further proving that 7th grade classes varies more.
C and D are irrelevant, and B says "varies less" which is the opposite of what's going on.
The bisector of an angle of a triangle divides the opposite side into segments that are proportional to the adjacent sides ⇒ AB/BC = AD/DC 36/27 = (42-x)/x 36x = 27(42-x) 36x = 1134 - 27x 36x + 27x = 1134 63x = 1134 x = 1134/63 x = 18