Let g be a positive, increasing function on the closed interval [1,5]. Four different numerical methods are used to estimate the average value of g on this interval.
I. Left–endpoint Riemann sum
II. Right–endpoint Riemann sum
III. Midpoint Riemann sum
IV. Trapezoidal approximation
Which method is most likely to give an overestimate of the average value?
a) I only
b) III only
c) II only
d) IV only