Achalasia is a rare disease that causes serious digestive distress to patients. Specialists perform an operation on the esophagus to remedy the situation. However, high blood pressure is a side effect...

Achalasia is a rare disease that causes serious digestive distress to patients. Specialists perform an operation on the esophagus to remedy the situation. However, high blood pressure is a side effect of this operation and the blood pressure of operated patients is believed to be 150 mmHg. A concerned specialist collected data on randomly selected 18 patients he operated on and found their average blood pressure to be 156 mmHg with a standard deviation of 12 mmHg. The p-value for a hypothesis test that investigates whether the operation causes higher blood pressure than the common belief is Blank 1. Fill in the blank, read surrounding text.
. (Assume blood pressure is approximately Normal)