If water depths of 7.2, -11.3, -20.3 and -20.1 cm are observed at clock times 29.8, 44.7, 59.6 and 74.5 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 44.7 and 59.6 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- 1.75), f(x) - .35, .25 f(x) and .25 f(x- 1.75) + .35. Quickly sketch each graph.