Statistical Power. The Statistical Data Analysis tutorial page provides a good background for understanding the concept of statistical power. In very basic terms, statistical power is the likelihood of achieving statistical significance, when in fact the alternative hypothesis is true.
In 2001, the U.S. Census Bureau estimated that nearly 7 million school-age children are routinely left home alone. âDevelopmentally, children are generally ready to be home alone around the age of 12 or 13,â says Cherie Sage, State Director of Safe Kids Kansas.
Surprisingly, most states don't have any minimum age requirements. The ones that do range from age 6 (a recommendation in Kansas) to 14 (required in Illinois). The most common ages, among the states that have a recommendation or legal requirement, are age 8, 10, and 12.