Final answer:
Without specific function values or a graph, the average rate of change of a quadratic function over an interval is calculated using the function's endpoint values divided by the interval width.
Step-by-step explanation:
The best estimate for the average rate of change of a quadratic function over an interval can be calculated using the function's values at the endpoints of the interval. Without the specific function or its graph provided, we cannot give a precise numerical answer, but the general approach is to subtract the function's value at the beginning of the interval from its value at the end and divide by the width of the interval. For a quadratic function f(t) = at² + bt + c, if you have the specific values for a, b, and c, you can calculate the function's values at any two points and use these to determine the average rate of change.