Step-by-step explanation:
the change rate between the data points gives us the print rate.
so,
(f(x2) - f(x1)) / (x2 - x1)
starting with x1 = 10 and x2 = 15 we see
(133 - 98) / (15 - 10) = 35/5 = 7
that means he is printing 7 pages per minute.
we see that we have the same difference (35 prints) for every following 5-minute interval.
so, that is the confirmed print rate.
and yes, the amount is increasing, of course.
after 10 minutes he has 98 flyers but we know he could have printed only 7×10 = 70 flyers in that time.
so, he started with 98-70 = 28 flyers before actually printing new ones.
