Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Name the sum of ERP W for class of d and frequency mhz of 98.7

### Inputs:
table_name: table, columns: ['Call sign', 'Frequency MHz', 'City of license', 'ERP W', 'Class', 'FCC info']

### Response:
SELECT SUM ERP W FROM table WHERE Class = d AND Frequency MHz = 98.7