Final answer:
The statement that must be true for the average rate of change of the function g(x) between x=4 and x=7 is C. (g(7) - g(4))/(7 - 4) = 5/6, which correctly represents the slope of the secant line between these two points on the function.
Step-by-step explanation:
The student asked about the average rate of change of a function g(x) between two points, x = 4 and x = 7. To find the average rate of change, you subtract the function values at these points and then divide by the difference in the x values, which gives us the formula:
(g(7) - g(4)) / (7 - 4)
Therefore, the statement that must be true is:
C. (g(7) - g(4))/(7 - 4) = 5/6
This formula represents the slope of the secant line that intersects the curve of g(x) at x = 4 and x = 7. Choice C is the correct expression of the average rate of change as it matches the formula for calculating it.