2.

Traffic engineers study how long the yellow light for a traffic signal should be. For one intersection, the number of seconds n required for a yellow light is related to the average approach speed v, in feet per second, by the following.

n = 1 + v/30 + 100/v

If the approach speed is 40 feet per second (about 27 miles per hour), how long should the yellow light be? (Round your answer to two decimal places.) _______ sec

4.

The following is a partial table of values for f = f (x). (Round your answers to two decimal places.)

x	0	2	4	6
f = f (x)	32.3	36.0	40.1	43.7

(a) Estimate the value of f (1) by averaging. (b) Find the average rate of change for f between x = 0 and x = 2.