Take your base cost and multiply by the percentage to find the increase. Then add to the base cost for the new monthly cost.
$45 x 0.07 = $3.15 increase
$45 + $3.15 = $48.15 new cost
D
all you need to do is add up all the numbers then divide it by the total of rolls he did. which was 20.
C. Circle graph
Hope this was any help