The graph of a function $f$ is given below. Estimate $\int_{0}^{\,8} {f(x)}\,dx$ using four subintervals with (a) right endpoints, (b) left endpoints, and (c) midpoints.

(a) $\int_{0}^{\,8} {f(x)}\,dx \approx$

(b) $\int_{0}^{\,8} {f(x)}\,dx \approx$

(c) $\int_{0}^{\,8} {f(x)}\,dx \approx$