Find the Average Rate of Change Illustrated in the Graph $C ( x ) = 1.30 x + 500 ; 46$

Multiple Choice

Find the average rate of change illustrated in the graph.
-Regrind, Inc. regrinds used typewriter platens. The variable cost to regrind each platen is $1.30. The total cost to regrind 110 platens is $500. Find the linear cost function to regrind platens. If reground platens sell for $9.60
Each, how many must be reground and sold to break even?

A) $C ( x ) = 1.30 x + 500 ; 46$ platens
B) $C ( x ) = 1.30 x + 357 ; 43$ platens
C) $C ( x ) = 1.30 x + 500$ ; 61 platens
D) $\mathrm { C } ( \mathrm { x } ) = 1.30 \mathrm { x } + 357 ; 33$ platens