If water depths of 63.7, 56.3, 52.2 and 51.3 cm are observed at clock times 14.6, 21.9, 29.2 and 36.5 sec, then at what average rate does the depth change during each time interval?

Sketch a graph of this data set and use a sketch to explain why the slope of this graph between 21.9 and 29.2 sec represents the average rate at which depth changes during this time interval.

 If f(x) = x², give the vertex and the three basic points of the graphs of f(x--.25), f(x) - 1.85, 2 f(x) and 2 f(x--.25) + 1.85. Quickly sketch each graph.