A train protection system automatically applies the brakes of a train if the speed limit for a segment of track is exceeded, or if the train enters a track segment that is currently signaled with a red light (i. e., the segment should not be entered). Giving reasons for your answer, explain which reliability metric you would use to specify the required reliability for such a system.

The most effective metric to use is the Probability of Failure on Demand .

Explanation:

The Probability of Failure on Demand  is the probability that a system will respond correctly if a request is made for the service at a given point in time.

The metrics of the protection system is used when the demands for sparse, in other words not frequent.

There are five requirements:

For instance, if there are 100 trains, each having 0.001 % chance, the probability of a train failing to stop is 0.0001

answer:

the fed will purchase bonds from banks to inject money into the banking system. the banks can use these funds to provide loans to individuals and businesses.

explanation: