Riemann Sum Trapezoid

Find the right-hand Riemann Sum, with three sub-intervals indicated by the table.

Use a trapezoidal sum with four intervals from the table to estimate the integral of 0 to 9 of V(t).
Hint: Since the $$\Delta X$$  is different use the area of a trapezoid formula!

A trapezoidal approximation is done for  $$f\left(x\right)=-x^3$$  on the interval (1,6). The approximation is an 

The table above gives the level of a person's cholesterol at different times during a 10-week treatment period. What is the level over this 10-week period obtained by using a Trapezoidal approximation with the sub-intervals [0,2] [2,6] and [6,10]

On a certain day, the rate at which material is deposited at a recycling center is modeled by the function R, where R(t) is measured in tons per hour and t is the number of hours since the center opened. Using a trapezoidal sum with three sub-intervals indicated by the data in the table, what is the approximate number of tons of material deposited in the first 9 hours since the center opened?