What Is the Value of the Estimate Using Four Approximating $\frac { 1 } { 2 }$

Multiple Choice

What is the value of the estimate using four approximating rectangles and taking sample points to be left-hand endpoints?

A) $\frac { 1 } { 2 }$
B) $\frac { 7 } { 4 }$

C) $\frac { 21 } { 8 }$
D) 3
E) $\frac { 15 } { 4 }$
F) $\frac { 29 } { 8 }$

G) $\frac { 9 } { 2 }$
H) 5