3.- If the number of steps increases, the number of rods also increases.
4.- In the graph is shown because of the stepness or a positive slope, in the table is shown because the number of steps increase each time just in one unit and the number of rods increases in 4 units or more.
5.- 90
because at 8 steps there are 48 rods, and before it the number of steps is increasing by one unit, then we must add 9 + 10 + 11 + 12 to 48
9 + 10 + 11 + 12 + 48 = 90