Below is an instruction that describes a task. Write a response that appropriately completes the request in Thai. Please answer in Thai.

### Instruction:
Kat gets a 95% on her first math test and an 80% on her second math test. If she wants an average grade of at least 90% in her math class, what does she need to get on her third final math test?

### Response:
 กำหนดให้ x = เปอร์เซ็นต์ที่ต้องการในการสอบคณิตศาสตร์ครั้งที่สาม
(95 + 80 + x)/3 = 90
(95 + 80 + x) = 270
x = 270 - 95 - 80
x = <<95=95>>95