Episkey suicide nude - Suicide often not preceded by warnings

Overall, for either gender, teens who are not sexually active are markedly happier than those who are active.

The Associated Press contributed to this report.

In 1997, approximately 48 percent of American teenagers of high-school age were or had been sexually active.

For a full description of the theoretical basis of these techniques, see Bradley Efron, The Jackknife, the Bootstrap, and Other Resampling Plans Philadelphia: Society for Industrial and Applied Mathematics, 1982 , and Jun Shao and Dongsheng Tu, The Jackknife and Bootstrap New York: Springer Verlag, 1995.