Please help. How do you read a graph and tell where the c's are?

Consider the following figure. Use the graph offto estimate the values ofcto the nearest 0.1 that satisfy the conclusion of the Mean Value Theorem for the interval [0, 8].

c= (smallest value)

c=

c=

c= (largest value)

http://www.webassign.net/scalc/4-2-8.gif