I don't know what to do with this. Help please.

Suppose that a volcano is erupting and readings of the rater(t) at which solid materials are spewed into the atmosphere are given in the table. The timetis measured in seconds and the units forr(t) are tonnes (metric tons) per second.

t=0, r(t)=2

t=1, r(t)=8

t=2, r(t)=26

t=3, r(t)=32

t=4, r(t)=46

t=5, r(t)=52

t=6, r(t)=60

(a) Give upper and lower estimates for the total quantityQ(6) of erupted materials after 6 seconds.

Q(6) = ? tonnes (lower estimate)

Q(6) = ? tonnes (upper estimate)

(b) Use the Midpoint Rule to estimateQ(6).

Q(6) = ? tonnes