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

### Instruction:
how many mean elevation with lowest point being gulf of mexico and state being texas

### Inputs:
table_name: table, columns: ['State', 'Highest point', 'Highest elevation', 'Lowest point', 'Lowest elevation', 'Mean elevation']

### Response:
SELECT COUNT Mean elevation FROM table WHERE Lowest point = Gulf of Mexico AND State = Texas