Calculate the average of the 4 student's grades.
87, 89, 92, 95
The average of the 4 student's grades is 90.75.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Calculate the average of the 4 student's grades.

### Response:
The average of the 4 student's grades is 90.75.