After a military campaign, a random sample of 59 soldiers (none of whom know each other) was examined and the number of soldiers who suffered from lifetime post-traumatic stress disorder (PTSD) was determined. Answer the following questions.
1. Explain why this is a binomial experiment.
2. Suppose that half of the former soldiers suffer from PTSD. What is the mean of X, the number of people suffering from PTSD in a sample of 59 former soldiers?
3. Interpret the mean.
4. Compute the standard deviation of X.
5. Would it be unusual to find 32 individuals suffering from PTSD in a group of 59 former soldiers? Explain your response.