The number of daily requests for emergency assistance at a fire station in a medium-sized city has the probability distribution shown here.
| y |
P(y) |
| 0 |
0.06 |
| 1 |
0.14 |
| 2 |
0.16 |
| 3 |
0.14 |
| 4 |
0.12 |
| 5 |
0.1 |
| 6 |
0.08 |
| 7 |
0.07 |
| 8 |
0.06 |
| 9 |
0.04 |
| 10 |
0.03 |
a. What is the probability that four or more requests will be made in a particular day?
b. What is the probability that the requests for assistance will be at least four but no more than six?
c. Suppose the fire station must call for additional equipment from a neighboring city whenever the number of requests for assistance exceeds eight in a given day. The neighboring city then charges for its equipment. What is the probability the city will call for additional equipment on a given day?