What if the number of debilitating network viruses detected in a day at the firewalls of an Internet Service Provider within a certain geographic region is fueling a possible management decision to upgrade the detection system. The decision will be made based on the results of the following data analysis. The mean number of network viruses detected in a day is 3.0. What is the probability that in any given day:

1. Zero network viruses will be detected?
2. Exactly one network virus will be detected?
3. Two or more network viruses will be detected?
4. Fewer than three network viruses will be detected?