A burrito company uses the function C(x) = 1.74x2 to calculate the number of calories in a tortilla with a diameter of x inches.
a) Find the average rates of change for the function over the intervals 6 < x < 8 and 9 < x < 11.
b) Interpret the average rates of change.
c) What does the difference in the average rates of change mean in terms of the situation?