Many veterans who bravely served in Iraq during Operation Enduring Freedom or Operation Iraqi Freedom have developed symptoms of post-traumatic stress disorder (PTSD) or similar ailments. A large study of returning veterans showed that 52.7% of the soldiers suffered from a PTSD or similar ailment after serving in Iraq. A random sample of 200 veterans from Iraq were selected for additional research. The number suffering from PTSD or a similar condition was recorded. (Source: Frayne SM, et al. (2010) Medical care needs of returning veterans with PTSD: their other burden. Journal of General Internal Medicine 26(1).)

Compute the standard deviation.