Coronary bypass surgery: The Agency for Healthcare Research and Quality reported that 53% of people who had coronary bypass surgery in a recent year were over the age of 65. Fifteen coronary bypass...

Coronary bypass surgery: The Agency for Healthcare Research and Quality reported that 53% of people who had coronary bypass surgery in a recent year were over the age of 65. Fifteen coronary bypass patients are sampled.

What is the standard deviation of the number of people over the age of 65 in a sample of 15 coronary bypass patients?