1.4 A courier company is interested in the length of time a certain set of traffic lights is on green. The lights have been set so that the longest possible time between green lights in any one direction is 2 minutes, and the shortest possible time is 15 seconds. An employee is instructed to observe the lights and record the length of time between consecutive green lights. (a) What is the variable of interest? (b) What is the sample space? (c) Can the classical approach to probability be used to determine P (less than 60 seconds between green lights)? Why or why not? (d) What about the relative frequency approach? If so, how? If not, why not?