1. gives the probability that waiting time will be in the neighborhood of a particular value.
2. gives the probability that waiting time will be less than or equal to a particular value.
3. gives the probability that waiting time will be more than or equal to a particular value.
4. gives none of the above.
Choose the correct option.
The correct answer is option 1. The probability density function, as we have been representing it, is a bell-shaped curve. The distances of the curve from the horizontal axis as we move along it give the probabilities that waiting time will be in the neighborhood of each particular value on that axis. The area under the curve to the left of any particular point on the horizontal axis gives the probability that waiting time will be less than that particular amount. And the area under the curve to the right of each point on the horizontal axis gives the probability that waiting time will be greater than that amount. The area under the curve to the left of a particular waiting time is called the cumulative probability, while the distance of the curve from the horizontal axis at each waiting time is called the probability density. The distance of the curve from the horizontal axis at any waiting time gives the change in the cumulative probability associated with a small change in the waiting time as well as the probability that it will take a waiting time within that small interval to find a job.